text: /*-------------------------------------------------------------------------
  This source file is a part of OGRE
  (Object-oriented Graphics Rendering Engine)
  
  For the latest info, see http://www.ogre3d.org/
  
  Copyright (c) 2000-2014 Torus Knot Software Ltd
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE
  
  You may alternatively use this source under the terms of a specific version of
  the OGRE Unrestricted License provided you have obtained such a license from
  Torus Knot Software Ltd.
  -------------------------------------------------------------------------*/
  #ifndef __SceneManager_H__
  #define __SceneManager_H__
  
  // Precompiler options
  #include "OgrePrerequisites.h"
  
  #include "OgrePlane.h"
  #include "OgreQuaternion.h"
  #include "OgreColourValue.h"
  #include "OgreSceneQuery.h"
  #include "OgreAutoParamDataSource.h"
  #include "OgreAnimationState.h"
  #include "OgreResourceGroupManager.h"
  #include "OgreRenderSystem.h"
  #include "OgreLodListener.h"
  #include "OgreRawPtr.h"
  #include "Math/Array/OgreNodeMemoryManager.h"
  #include "Math/Array/OgreObjectMemoryManager.h"
  #include "Animation/OgreSkeletonAnimManager.h"
  #include "Compositor/Pass/OgreCompositorPass.h"
  #include "Threading/OgreThreads.h"
  #include "OgreHeaderPrefix.h"
  
  namespace Ogre {
      /** \addtogroup Core
      *  @{
      */
      /** \addtogroup Scene
      *  @{
      */
  
      typedef vector<TextureGpu*>::type TextureGpuVec;
  
      /** Structure for holding a position & orientation pair. */
      struct ViewPoint
      {
          Vector3 position;
          Quaternion orientation;
      };
  
      typedef FastArray<MovableObject::MovableObjectArray> VisibleObjectsPerRq;
      typedef FastArray<VisibleObjectsPerRq> VisibleObjectsPerThreadArray;
  
      // Forward declarations
      class DefaultIntersectionSceneQuery;
      class DefaultRaySceneQuery;
      class DefaultSphereSceneQuery;
      class DefaultAxisAlignedBoxSceneQuery;
      class LodListener;
      struct MovableObjectLodChangedEvent;
      struct EntityMeshLodChangedEvent;
      struct EntityMaterialLodChangedEvent;
      class CompositorShadowNode;
      class UniformScalableTask;
  
      class RadialDensityMask;
  
      namespace v1
      {
          class Rectangle2D;
      }
  
      /// All variables are read-only for the worker threads.
      struct CullFrustumRequest
      {
          typedef vector<ObjectMemoryManager*>::type ObjectMemoryManagerVec;
          /// First RenderQueue ID to render (inclusive)
          uint8                           firstRq;
          /// Last RenderQueue ID to render (exclusive)
          uint8                           lastRq;
          /// Whether this is a shadow mapping pass
          bool                            casterPass;
          /// Whether we should immediately add to render queue v2 objects
          bool                            addToRenderQueue;
          bool                            cullingLights;
          /** Memory manager of the objects to cull. Could contain all Lights, all Entity, etc.
              Could be more than one depending on the high level cull system (i.e. tree-based sys)
              Must be const (it is read only for all threads).
          */
          ObjectMemoryManagerVec const    *objectMemManager;
          /// Camera whose frustum we're to cull against. Must be const (read only for all threads).
          Camera const                    *camera;
          /// Camera whose frustum we're to cull against. Must be const (read only for all threads).
          Camera const                    *lodCamera;
  
          CullFrustumRequest() :
              firstRq( 0 ), lastRq( 0 ), casterPass( false ), addToRenderQueue( true ),
              cullingLights( false ), objectMemManager( 0 ), camera( 0 ), lodCamera( 0 )
          {
          }
          CullFrustumRequest( uint8 _firstRq, uint8 _lastRq, bool _casterPass,
                              bool _addToRenderQueue, bool _cullingLights,
                              const ObjectMemoryManagerVec *_objectMemManager,
                              const Camera *_camera, const Camera *_lodCamera ) :
              firstRq( _firstRq ), lastRq( _lastRq ), casterPass( _casterPass ),
              addToRenderQueue( _addToRenderQueue ), cullingLights( _cullingLights ),
              objectMemManager( _objectMemManager ), camera( _camera ), lodCamera( _lodCamera )
          {
          }
      };
  
      struct UpdateLodRequest : public CullFrustumRequest
      {
          Real    lodBias;
  
          UpdateLodRequest() :
              CullFrustumRequest(), lodBias( 0 )
          {
          }
          UpdateLodRequest( uint8 _firstRq, uint8 _lastRq,
                              const ObjectMemoryManagerVec *_objectMemManager,
                              const Camera *_camera, const Camera *_lodCamera, Real _lodBias ) :
              CullFrustumRequest( _firstRq, _lastRq, false, false, false,
                                  _objectMemManager, _camera, _lodCamera ),
              lodBias( _lodBias )
          {
          }
      };
  
      struct UpdateTransformRequest
      {
          Transform t;
          /// Number of nodes to process for each thread. Must be multiple of ARRAY_PACKED_REALS
          size_t numNodesPerThread;
          size_t numTotalNodes;
  
          UpdateTransformRequest() :
              numNodesPerThread( 0 ), numTotalNodes( 0 ) {}
  
          UpdateTransformRequest( const Transform &_t, size_t _numNodesPerThread, size_t _numTotalNodes ) :
              t( _t ), numNodesPerThread( _numNodesPerThread ), numTotalNodes( _numTotalNodes )
          {
          }
      };
  
      struct BuildLightListRequest
      {
          size_t startLightIdx;
  
          BuildLightListRequest() :
              startLightIdx( 0 ) {}
          BuildLightListRequest( size_t _startLightIdx ) :
              startLightIdx( _startLightIdx )
          {
          }
      };
  
      /** Struct that holds a number of cameras used in the current rendering pass
       */
      struct CamerasInProgress
      {
          const Camera *renderingCamera;
          const Camera *cullingCamera;
          const Camera *lodCamera;
  
          CamerasInProgress():
              renderingCamera(0), cullingCamera(0), lodCamera(0) {}
          CamerasInProgress( const Camera* camera ) :
              renderingCamera(camera), cullingCamera(camera), lodCamera(camera) {}
          CamerasInProgress( const Camera *_renderingCamera, const Camera *_cullingCamera,
                             const Camera *_lodCamera ) :
              renderingCamera(_renderingCamera), cullingCamera(_cullingCamera), lodCamera(_lodCamera) {}
      };
  
      /** Manages the organisation and rendering of a 'scene' i.e. a collection 
          of objects and potentially world geometry.
      @remarks
          This class defines the interface and the basic behaviour of a 
          'Scene Manager'. A SceneManager organises the culling and rendering of
          the scene, in conjunction with the RenderQueue. This class is designed 
          to be extended through subclassing in order to provide more specialised
          scene organisation structures for particular needs. The default 
          SceneManager culls based on a hierarchy of node bounding boxes, other
          implementations can use an octree (@see OctreeSceneManager), a BSP
          tree (@see BspSceneManager), and many other options. New SceneManager
          implementations can be added at runtime by plugins, see 
          SceneManagerEnumerator for the interfaces for adding new SceneManager
          types.
      @par
          There is a distinction between 'objects' (which subclass MovableObject, 
          and are movable, discrete objects in the world), and 'world geometry',
          which is large, generally static geometry. World geometry tends to 
          influence the SceneManager organisational structure (e.g. lots of indoor
          static geometry might result in a spatial tree structure) and as such
          world geometry is generally tied to a given SceneManager implementation,
          whilst MovableObject instances can be used with any SceneManager.
          Subclasses are free to define world geometry however they please.
      @par
          Multiple SceneManager instances can exist at one time, each one with 
          a distinct scene. Which SceneManager is used to render a scene is
          dependent on the Camera, which will always call back the SceneManager
          which created it to render the scene. 
       */
      class _OgreExport SceneManager : public SceneMgtAlignedAlloc, public IdObject
      {
      public:
          /// Default query mask for entities @see SceneQuery
          static uint32 QUERY_ENTITY_DEFAULT_MASK;
          /// Default query mask for effects like billboardsets / particle systems @see SceneQuery
          static uint32 QUERY_FX_DEFAULT_MASK;
          /// Default query mask for StaticGeometry  @see SceneQuery
          static uint32 QUERY_STATICGEOMETRY_DEFAULT_MASK;
          /// Default query mask for lights  @see SceneQuery
          static uint32 QUERY_LIGHT_DEFAULT_MASK;
          /// Default query mask for frusta and cameras @see SceneQuery
          static uint32 QUERY_FRUSTUM_DEFAULT_MASK;
  
          /// Describes the stage of rendering when performing complex illumination
          enum IlluminationRenderStage
          {
              /// No special illumination stage
              IRS_NONE,
              /// Render to texture stage, used for texture based shadows
              IRS_RENDER_TO_TEXTURE
          };
  
          typedef vector<SceneNode*>::type SceneNodeList;
          typedef vector<MovableObject*>::type MovableObjectVec;
  
          /** Class that allows listening in on the various stages of SceneManager
              processing, so that custom behaviour can be implemented from outside.
          */
          class Listener
          {
          public:
              Listener() {}
              virtual ~Listener() {}
  
              /** Called prior to searching for visible objects in this SceneManager.
              @remarks
                  Note that the render queue at this stage will be full of the last
                  render's contents and will be cleared after this method is called.
              @param source The SceneManager instance raising this event.
              @param irs The stage of illumination being dealt with. IRS_NONE for 
                  a regular render, IRS_RENDER_TO_TEXTURE for a shadow caster render.
              @param v The viewport being updated. You can get the camera from here.
              */
              virtual void preFindVisibleObjects(SceneManager* source, 
                  IlluminationRenderStage irs, Viewport* v)
                          { (void)source; (void)irs; (void)v; }
  
              /** Called after searching for visible objects in this SceneManager.
              @remarks
                  Note that the render queue at this stage will be full of the current
                  scenes contents, ready for rendering. You may manually add renderables
                  to this queue if you wish.
              @param source The SceneManager instance raising this event.
              @param irs The stage of illumination being dealt with. IRS_NONE for 
                  a regular render, IRS_RENDER_TO_TEXTURE for a shadow caster render.
              @param v The viewport being updated. You can get the camera from here.
              */
              virtual void postFindVisibleObjects(SceneManager* source, 
                  IlluminationRenderStage irs, Viewport* v)
                          { (void)source; (void)irs; (void)v; }
  
              /** Event raised after all shadow textures have been rendered into for 
                  all queues / targets but before any other geometry has been rendered
                  (including main scene geometry). 
              @remarks
                  This callback is useful for those that wish to perform some 
                  additional processing on shadow textures before they are used to 
                  render shadows. For example you could perform some filtering by 
                  rendering the existing shadow textures into another alternative 
                  shadow texture with a shader.]
              @note
                  This event will only be fired when texture shadows are in use.
              @param numberOfShadowTextures The number of shadow textures in use
              */
              virtual void shadowTexturesUpdated(size_t numberOfShadowTextures)
                          { (void)numberOfShadowTextures; }
  
              /** This event occurs just before the view & projection matrices are
                  set for rendering into a shadow texture.
              @remarks
                  You can use this event hook to perform some custom processing,
                  such as altering the camera being used for rendering the light's
                  view, including setting custom view & projection matrices if you
                  want to perform an advanced shadow technique.
              @note
                  This event will only be fired when texture shadows are in use.
              @param light Pointer to the light for which shadows are being rendered
              @param camera Pointer to the camera being used to render
              @param iteration For lights that use multiple shadow textures, the iteration number
              */
              virtual void shadowTextureCasterPreViewProj( const Light* light, 
                  Camera* camera, size_t iteration)
                          { (void)light; (void)camera; (void)iteration; }
  
              /** Hook to allow the listener to override the ordering of lights for
                  the entire frustum.
              @remarks
                  Whilst ordinarily lights are sorted per rendered object 
                  (@see MovableObject::queryLights), texture shadows adds another issue
                  in that, given there is a finite number of shadow textures, we must
                  choose which lights to render texture shadows from based on the entire
                  frustum. These lights should always be listed first in every objects
                  own list, followed by any other lights which will not cast texture 
                  shadows (either because they have shadow casting off, or there aren't
                  enough shadow textures to service them).
              @par
                  This hook allows you to override the detailed ordering of the lights
                  per frustum. The default ordering is shadow casters first (which you 
                  must also respect if you override this method), and ordered
                  by distance from the camera within those 2 groups. Obviously the closest
                  lights with shadow casting enabled will be listed first. Only lights 
                  within the range of the frustum will be in the list.
              @param lightList The list of lights within range of the frustum which you
                  may sort.
              @return true if you sorted the list, false otherwise.
              */
              virtual bool sortLightsAffectingFrustum(LightList& lightList)
                          { (void)lightList; return false; }
  
              /** Event notifying the listener of the SceneManager's destruction. */
              virtual void sceneManagerDestroyed(SceneManager* source)
                          { (void)source; }
          };
  
          enum EnvFeatures
          {
              /// Normally environmental cubemap probes are used for specular reflection
              /// When this flag is present, the higest mip is used as an approximation
              /// for diffuse indirect illumination.
              /// Do not set this flag if you don't want this behavior (i.e. because
              /// the diffuse GI is already gathered from another source of information)
              EnvFeatures_DiffuseGiFromReflectionProbe = 1u << 0u,
          };
  
      protected:
          /// Subclasses can override this to ensure their specialised SceneNode is used.
          virtual SceneNode* createSceneNodeImpl( SceneNode *parent,
                                                  NodeMemoryManager *nodeMemoryManager );
          virtual TagPoint* createTagPointImpl( SceneNode *parent,
                                                NodeMemoryManager *nodeMemoryManager );
  
          typedef vector<NodeMemoryManager*>::type NodeMemoryManagerVec;
          typedef vector<ObjectMemoryManager*>::type ObjectMemoryManagerVec;
          typedef vector<SkeletonAnimManager*>::type SkeletonAnimManagerVec;
  
          /** These are the main memory managers. Note that some Scene Managers may have more than one
              memory manager (eg. one per Octant in an Octree implementation, one per Portal, etc)
              Those managers can, at the start of scene graph update, transfer/move the objects created
              in the main mem. managers into their localized versions.
  
              During @see highLevelCull, those scene managers will update mNodeMemoryManagerCulledList
              and co. to indicate which memory managers should be traversed for rendering.
          */
          NodeMemoryManager       mNodeMemoryManager[NUM_SCENE_MEMORY_MANAGER_TYPES];
          ObjectMemoryManager     mEntityMemoryManager[NUM_SCENE_MEMORY_MANAGER_TYPES];
          ObjectMemoryManager     mLightMemoryManager;
          ObjectMemoryManager     mForwardPlusMemoryManager[NUM_SCENE_MEMORY_MANAGER_TYPES];
          SkeletonAnimManager     mSkeletonAnimationManager;
          NodeMemoryManager       mTagPointNodeMemoryManager;
          /// Filled and cleared every frame in HighLevelCull()
          NodeMemoryManagerVec    mNodeMemoryManagerUpdateList;
          NodeMemoryManagerVec    mTagPointNodeMemoryManagerUpdateList;
          ObjectMemoryManagerVec  mEntitiesMemoryManagerCulledList;
          ObjectMemoryManagerVec  mEntitiesMemoryManagerUpdateList;
          ObjectMemoryManagerVec  mLightsMemoryManagerCulledList;
          ObjectMemoryManagerVec  mForwardPlusMemoryManagerCullList;
          SkeletonAnimManagerVec  mSkeletonAnimManagerCulledList;
  
          uint32                  mNumDecals;
          uint32                  mNumCubemapProbes;
  
          /** Minimum depth level at which mNodeMemoryManager[SCENE_STATIC] is dirty.
          @remarks
              We do an optimization: We know for sure that if node at level N became dirty,
              we only need to update nodes starting from level N, N+1, N+2, ..., N+n
              No need to update between level 0, 1, 2, ..., N-1
          */
          uint16                  mStaticMinDepthLevelDirty;
  
          /** Whether mEntityMemoryManager[SCENE_STATIC] is dirty (assume all render queues,
              you shouldn't be doing this often anyway!)
          */
          bool                    mStaticEntitiesDirty;
  
          PrePassMode             mPrePassMode;
          TextureGpuVec   mPrePassTextures;
          TextureGpu      *mPrePassDepthTexture;
          TextureGpu      *mSsrTexture;
          TextureGpu      *mPassDepthTextureNoMsaa;
          TextureGpu      *mRefractionsTexture;
  
          /// See CompositorPassSceneDef::mUvBakingSet
          uint8       mUvBakingSet;
          Vector2     mUvBakingOffset;
  
          /// Instance name
          String mName;
  
          /// Queue of objects for rendering
          RenderQueue* mRenderQueue;
  
          ForwardPlusBase *mForwardPlusSystem;
          ForwardPlusBase *mForwardPlusImpl;
          bool mBuildLegacyLightList;
  
          TextureGpu *mDecalsDiffuseTex;
          TextureGpu *mDecalsNormalsTex;
          TextureGpu *mDecalsEmissiveTex;
  
          /// Updated every frame, has enough memory to hold all lights.
          /// The order is not deterministic, it depends on the number
          /// of worker threads.
          LightListInfo mGlobalLightList;
          typedef FastArray<LightArray> LightArrayPerThread;
          typedef FastArray<BuildLightListRequest> BuildLightListRequestPerThread;
          LightArrayPerThread             mGlobalLightListPerThread;
          BuildLightListRequestPerThread  mBuildLightListRequestPerThread;
  
          /// Current ambient light.
          ColourValue mAmbientLight[2];
          Vector3     mAmbientLightHemisphereDir;
          uint32      mEnvFeatures;
  
          float       mAmbientSphericalHarmonics[9u*3u];
  
          /// The rendering system to send the scene to
          RenderSystem *mDestRenderSystem;
  
          typedef vector<Camera*>::type CameraList;
          typedef map<IdString, Camera*>::type CameraMap;
  
          /** Central list of cameras - for easy memory management and lookup.
          */
          CameraList  mCameras;
          CameraMap   mCamerasByName;
          FrustumVec  mVisibleCameras;
          FrustumVec  mCubeMapCameras;
  
          typedef vector<WireAabb*>::type WireAabbVec;
          WireAabbVec mTrackingWireAabbs;
  
          typedef map<String, v1::StaticGeometry* >::type StaticGeometryList;
          StaticGeometryList mStaticGeometryList;
  
          /** Central list of SceneNodes - for easy memory management.
              @note
                  Note that this list is used only for memory management; the structure of the scene
                  is held using the hierarchy of SceneNodes starting with the root node. However you
                  can look up nodes this way.
          */
          SceneNodeList   mSceneNodes;
          SceneNodeList   mSceneNodesWithListeners;
  
          /// Cameras in progress
          CamerasInProgress mCamerasInProgress;
          /// Current Viewport
          Viewport *mCurrentViewport0;
  
          CompositorPass          *mCurrentPass;
          CompositorShadowNode    *mCurrentShadowNode;
          bool                    mShadowNodeIsReused;
  
          /// Root scene node
          SceneNode* mSceneRoot[NUM_SCENE_MEMORY_MANAGER_TYPES];
          SceneNode* mSceneDummy;
  
          /// Autotracking scene nodes
  		struct AutoTrackingSceneNode
  		{
  			SceneNode *source;
  			SceneNode *target;
  			/// Tracking offset for fine tuning
  			Vector3		offset;
  			/// Local 'normal' direction vector
  			Vector3		localDirection;
  
  			AutoTrackingSceneNode( SceneNode *_source, SceneNode *_target,
  								   const Vector3 &_offset, const Vector3 &_localDirection ) :
  				source( _source ), target( _target ),
  				offset( _offset ), localDirection( _localDirection )
  			{
  			}
  		};
  
  		typedef vector<AutoTrackingSceneNode>::type AutoTrackingSceneNodeVec;
          AutoTrackingSceneNodeVec mAutoTrackingSceneNodes;
  
      public:
          enum SkyMethod
          {
              SkyCubemap,
              SkyEquirectangular
          };
      protected:
          SkyMethod mSkyMethod;
          Rectangle2D *mSky;
          MaterialPtr mSkyMaterial;
  
          /// For VR optimization
          RadialDensityMask *mRadialDensityMask;
  
          // Fog
          FogMode mFogMode;
          ColourValue mFogColour;
          Real mFogStart;
          Real mFogEnd;
          Real mFogDensity;
          
          unsigned long mLastFrameNumber;
          OGRE_SIMD_ALIGNED_DECL( Matrix4, mTempXform[256] );
          bool mResetIdentityView;
          bool mResetIdentityProj;
  
          bool mFlipCullingOnNegativeScale;
          CullingMode mPassCullingMode;
  
      protected:
          /// Array defining shadow texture index in light list.
          vector<size_t>::type mShadowTextureIndexLightList;
  
          /// Cached light information, used to tracking light's changes
          struct _OgreExport LightInfo
          {
              Light* light;       /// Just a pointer for comparison, the light might destroyed for some reason
              int type;           /// Use int instead of Light::LightTypes to avoid header file dependence
              Real range;         /// Sets to zero if directional light
              Vector3 position;   /// Sets to zero if directional light
              uint32 lightMask;   /// Light mask
  
              bool operator== (const LightInfo& rhs) const
              {
                  return light == rhs.light && type == rhs.type &&
                      range == rhs.range && position == rhs.position && lightMask == rhs.lightMask;
              }
  
              bool operator!= (const LightInfo& rhs) const
              {
                  return !(*this == rhs);
              }
          };
  
          typedef vector<LightInfo>::type LightInfoList;
  
          /// Simple structure to hold MovableObject map and a mutex to go with it.
          struct MovableObjectCollection
          {
              MovableObjectVec movableObjects;
              OGRE_MUTEX(mutex);
          };
          typedef map<String, MovableObjectCollection*>::type MovableObjectCollectionMap;
          MovableObjectCollectionMap mMovableObjectCollectionMap;
          /** Gets the movable object collection for the given type name.
          @remarks
              This method create new collection if the collection does not exist.
          */
          MovableObjectCollection* getMovableObjectCollection(const String& typeName);
          /** Gets the movable object collection for the given type name.
          @remarks
              This method throw exception if the collection does not exist.
          */
          const MovableObjectCollection* getMovableObjectCollection(const String& typeName) const;
          /// Mutex over the collection of MovableObject types
          OGRE_MUTEX(mMovableObjectCollectionMapMutex);
  
          /// A pass designed to let us render shadow colour on white for texture shadows
          Pass* mShadowCasterPlainBlackPass;
          /** Internal method for turning a regular pass into a shadow caster pass.
          @remarks
              This is only used for texture shadows, basically we're trying to
              ensure that objects are rendered solid black.
              This method will usually return the standard solid black pass for
              all fixed function passes, but will merge in a vertex program
              and fudge the AutoParamDataSource to set black lighting for
              passes with vertex programs. 
          */
          virtual_l2 const Pass* deriveShadowCasterPass(const Pass* pass);
      
          /** Internal method to validate whether a Pass should be allowed to render.
          @remarks
              Called just before a pass is about to be used for rendering a group to
              allow the SceneManager to omit it if required. A return value of false
              skips this pass. 
          */
          virtual_l2 bool validatePassForRendering(const Pass* pass);
  
          enum BoxPlane
          {
              BP_FRONT = 0,
              BP_BACK = 1,
              BP_LEFT = 2,
              BP_RIGHT = 3,
              BP_UP = 4,
              BP_DOWN = 5
          };
  
          /// Flag indicating whether SceneNodes will be rendered as a set of 3 axes
          bool mDisplayNodes;
  
          /// Storage of animations, lookup by name
          typedef map<String, v1::Animation*>::type AnimationList;
          AnimationList mAnimationsList;
          OGRE_MUTEX(mAnimationsListMutex);
          v1::AnimationStateSet mAnimationStates;
  
  
          /** Internal method used by _renderSingleObject to deal with renderables
              which override the camera's own view / projection materices. */
          virtual void useRenderableViewProjMode(const Renderable* pRend, bool fixedFunction);
          
          /** Internal method used by _renderSingleObject to deal with renderables
              which override the camera's own view / projection matrices. */
          virtual void resetViewProjMode(bool fixedFunction);
  
          typedef vector<RenderQueueListener*>::type RenderQueueListenerList;
          RenderQueueListenerList mRenderQueueListeners;
  
          typedef vector<RenderObjectListener*>::type RenderObjectListenerList;
          RenderObjectListenerList mRenderObjectListeners;
          typedef vector<Listener*>::type ListenerList;
          ListenerList mListeners;
          /// Internal method for firing the queue start event, returns true if queue is to be skipped
          virtual bool fireRenderQueueStarted(uint8 id, const String& invocation);
          /// Internal method for firing the queue end event, returns true if queue is to be repeated
          virtual bool fireRenderQueueEnded(uint8 id, const String& invocation);
          /// Internal method for firing when rendering a single object.
          virtual void fireRenderSingleObject(Renderable* rend, const Pass* pass,
                                              const AutoParamDataSource* source,
                                              const LightList* pLightList,
                                              bool suppressRenderStateChanges);
  
          /// Internal method for firing the texture shadows updated event
          virtual void fireShadowTexturesUpdated(size_t numberOfShadowTextures);
          /// Internal method for firing the pre caster texture shadows event
          virtual void fireShadowTexturesPreCaster(const Light* light, Camera* camera, size_t iteration);
          /// Internal method for firing find visible objects event
          virtual void firePreFindVisibleObjects(Viewport* v);
          /// Internal method for firing find visible objects event
          virtual void firePostFindVisibleObjects(Viewport* v);
          /// Internal method for firing destruction event
          virtual void fireSceneManagerDestroyed();
          /** Internal method for setting the destination viewport for the next render. */
          virtual void setViewports( Viewport **vp, size_t numViewports );
  
          /** Flag that indicates if all of the scene node's bounding boxes should be shown as a wireframe. */
          bool mShowBoundingBoxes;
  
          /** Internal utility method for rendering a single object. 
          @remarks
              Assumes that the pass has already been set up.
          @param rend The renderable to issue to the pipeline
          @param pass The pass which is being used
          @param lightScissoringClipping If true, passes that have the getLightScissorEnabled
              and/or getLightClipPlanesEnabled flags will cause calculation and setting of 
              scissor rectangle and user clip planes. 
          @param doLightIteration If true, this method will issue the renderable to
              the pipeline possibly multiple times, if the pass indicates it should be
              done once per light
          @param manualLightList Only applicable if doLightIteration is false, this
              method allows you to pass in a previously determined set of lights
              which will be used for a single render of this object.
          */
          virtual_l1 void renderSingleObject(Renderable* rend, const Pass* pass, 
              bool lightScissoringClipping, bool doLightIteration);
  
          /** Internal method for creating the AutoParamDataSource instance. */
          virtual AutoParamDataSource* createAutoParamDataSource(void) const
          {
              return OGRE_NEW AutoParamDataSource();
          }
  
          /// Utility class for calculating automatic parameters for gpu programs
          AutoParamDataSource* mAutoParamDataSource;
  
          bool mLateMaterialResolving;
  
          ColourValue mShadowColour;
          Real mShadowDirLightExtrudeDist;
          IlluminationRenderStage mIlluminationStage;
          /// Struct for caching light clipping information for re-use in a frame
          struct LightClippingInfo
          {
              RealRect scissorRect;
              PlaneList clipPlanes;
              bool scissorValid;
              unsigned long clipPlanesValid;
              LightClippingInfo() : scissorValid(false), clipPlanesValid(false) {}
  
          };
          typedef map<Light const *, LightClippingInfo>::type LightClippingInfoMap;
          LightClippingInfoMap mLightClippingInfoMap;
          unsigned long mLightClippingInfoMapFrameNumber;
  
          /** To be used with MovableObjects. Checks that the input pointer's mGlobalIndex
              is consistent with the container, otherwise there's a bug and mGlobalIndex
              is out of date (or could be caused by memory corruption, of course)
          @remarks
              It is a template since it's legal to pass a vector<Camera> since Camera
              is derived from MovableObject too; but would fail compilation.
          @param container
              The container that allegedly holds the mo.
          @param mo
              MovableObject whose integrity is going to be checked
          */
          template<typename T>
          void checkMovableObjectIntegrity( const typename vector<T*>::type &container,
                                              const T *mo ) const;
  
          /** Culls the scene in a high level fashion (i.e. Octree, Portal, etc.) by taking into account all
              registered cameras. Produces a list of culled Entities & SceneNodes that must follow a very
              strict set of rules:
                  * Entities are separated by RenderQueue
                  * Entities sharing the same skeleton need to be adjacent (TODO: Required? dark_sylinc)
                  * SceneNodes must be separated by hierarchy depth and must be contiguous within the same
                    depth level. (@see mNodeMemoryManagerCulledList)
            @remarks
              The default implementation just returns all nodes in the scene. @See updateAllTransforms
              @see updateSceneGraph
          */
          virtual void highLevelCull();
  
          /** Permanently applies the relative origin change and propagates to children nodes
          @remarks
              Relative origins should happen at the root level. If both a parent & children apply
              the relative origin, we would be applying the offset twice.
              This algorithm works by analyzing if we can keep moving the change to children nodes.
              We can only do so if the parent node doesn't have attachments, or if their attachments
              are all Cameras.
          */
          void propagateRelativeOrigin( SceneNode *sceneNode, const Vector3 &relativeOrigin );
          
      public:
  
          AutoParamDataSource *_getAutoParamDataSource(void) const    { return mAutoParamDataSource; }
  
          //A render context, used to store internal data for pausing/resuming rendering
          struct RenderContext
          {
              RenderQueue* renderQueue;   
              Viewport* viewport;
              CamerasInProgress camerasInProgress;
              RenderSystem::RenderSystemContext* rsContext;
          };
  
          /** Pause rendering of the frame. This has to be called when inside a renderScene call
              (Usually using a listener of some sort)
          */
          virtual RenderContext* _pauseRendering();
          /** Resume rendering of the frame. This has to be called after a _pauseRendering call
          @param context The rendring context, as returned by the _pauseRendering call
          */
          virtual void _resumeRendering(RenderContext* context);
  
      protected:
          Real mDefaultShadowFarDist;
          Real mDefaultShadowFarDistSquared;
          Real mShadowTextureOffset; /// Proportion of texture offset in view direction e.g. 0.4
          Real mShadowTextureFadeStart; /// As a proportion e.g. 0.6
          Real mShadowTextureFadeEnd; /// As a proportion e.g. 0.9
          Pass* mShadowTextureCustomCasterPass;
          String mShadowTextureCustomCasterVertexProgram;
          String mShadowTextureCustomCasterFragmentProgram;
          GpuProgramParametersSharedPtr mShadowTextureCustomCasterVPParams;
          GpuProgramParametersSharedPtr mShadowTextureCustomCasterFPParams;
  
          CompositorTextureVec        mCompositorTextures;
  
          /// Visibility mask used to show / hide objects
          uint32 mVisibilityMask;
          uint32 mLightMask;
          bool mFindVisibleObjects;
  
          enum RequestType
          {
              CULL_FRUSTUM,
              UPDATE_ALL_ANIMATIONS,
              UPDATE_ALL_TRANSFORMS,
              UPDATE_ALL_BONE_TO_TAG_TRANSFORMS,
              UPDATE_ALL_TAG_ON_TAG_TRANSFORMS,
              UPDATE_ALL_BOUNDS,
              UPDATE_ALL_LODS,
              BUILD_LIGHT_LIST01,
              BUILD_LIGHT_LIST02,
              USER_UNIFORM_SCALABLE_TASK,
              STOP_THREADS,
              NUM_REQUESTS
          };
  
          size_t  mNumWorkerThreads;
          bool    mForceMainThread;
  
          CullFrustumRequest              mCurrentCullFrustumRequest;
          UpdateLodRequest                mUpdateLodRequest;
          UpdateTransformRequest          mUpdateTransformRequest;
          ObjectMemoryManagerVec const    *mUpdateBoundsRequest;
          UniformScalableTask *mUserTask;
          RequestType         mRequestType;
          Barrier             *mWorkerThreadsBarrier;
          ThreadHandleVec     mWorkerThreads;
  
          /** Contains MovableObjects to be visited and rendered.
          @rermarks
              Declared here to avoid allocating and deallocating every frame. Declared as array of
              arrays (vector of vectors) for multithreading purposes (put results in one array while
              another thread stores in the other array). @See cullFrustum
          */
          VisibleObjectsPerThreadArray mVisibleObjects;
  
          /** @See mVisibleObjects. This one is a variable used for temporary storage by (eg.) Instance
              Managers to cull their internal instanced entities from multiple threads. We do not
              guarantee that those who acquired our data retain sole ownership; thus extra care may
              be needed to ensure that no two separate systems request this variable at the same time
              Retrieve this buffer using @see _getTmpVisibleObjectsList
          */
          VisibleObjectsPerThreadArray mTmpVisibleObjects;
  
          /// Suppress render state changes?
          bool mSuppressRenderStateChanges;
  
          /// Set up a scissor rectangle from a group of lights
          virtual ClipResult buildAndSetScissor(const LightList& ll, const Camera* cam);
          /// Update a scissor rectangle from a single light
          virtual void buildScissor(const Light* l, const Camera* cam, RealRect& rect);
          /// Build a set of user clip planes from a single non-directional light
          virtual ClipResult buildAndSetLightClip(const LightList& ll);
          virtual void buildLightClip(const Light* l, PlaneList& planes);
          virtual void resetLightClip();
          virtual void checkCachedLightClippingInfo();
  
          /// Whether to use camera-relative rendering
          Matrix4 mCachedViewMatrix;
          Vector3 mRelativeOffset;
  
          /// Last light sets
          uint32 mLastLightHash;
          unsigned short mLastLightLimit;
          uint32 mLastLightHashGpuProgram;
          /// Gpu params that need rebinding (mask of GpuParamVariability)
          uint16 mGpuParamsDirty;
  
          virtual void useLights(const LightList& lights, unsigned short limit);
          virtual void setViewMatrix(const Matrix4& m);
          virtual void useLightsGpuProgram(const Pass* pass, const LightList* lights);
          virtual void updateGpuProgramParameters(const Pass* p);
  
  
  
  
  
  
  
  
          /// Set of registered LOD listeners
          typedef set<LodListener*>::type LodListenerSet;
          LodListenerSet mLodListeners;
  
          /// List of movable object LOD changed events
          typedef vector<MovableObjectLodChangedEvent>::type MovableObjectLodChangedEventList;
          MovableObjectLodChangedEventList mMovableObjectLodChangedEvents;
  
          /// List of entity mesh LOD changed events
          typedef vector<EntityMeshLodChangedEvent>::type EntityMeshLodChangedEventList;
          EntityMeshLodChangedEventList mEntityMeshLodChangedEvents;
  
          /// List of entity material LOD changed events
          typedef vector<EntityMaterialLodChangedEvent>::type EntityMaterialLodChangedEventList;
          EntityMaterialLodChangedEventList mEntityMaterialLodChangedEvents;
  
          /** Updates the Animations from the given request inside a thread. @See updateAllAnimations
          @param threadIdx
              Thread index so we know at which point we should start at.
              Must be unique for each worker thread
          */
          void updateAllAnimationsThread( size_t threadIdx );
          void updateAnimationTransforms( BySkeletonDef &bySkeletonDef, size_t threadIdx );
  
          /** Updates the Nodes from the given request inside a thread. @See updateAllTransforms
          @param request
              Fully setup request. @See UpdateTransformRequest.
          @param threadIdx
              Thread index so we know at which point we should start at.
              Must be unique for each worker thread
          */
          void updateAllTransformsThread( const UpdateTransformRequest &request, size_t threadIdx );
  
          /// @see TagPoint::updateAllTransformsBoneToTag
          void updateAllTransformsBoneToTagThread( const UpdateTransformRequest &request,
                                                   size_t threadIdx );
  
          /// @see TagPoint::updateAllTransformsTagOnTag
          void updateAllTransformsTagOnTagThread( const UpdateTransformRequest &request,
                                                  size_t threadIdx );
  
          /** Updates the world aabbs from the given request inside a thread. @See updateAllTransforms
          @param threadIdx
              Thread index so we know at which point we should start at.
              Must be unique for each worker thread
          */
          void updateAllBoundsThread( const ObjectMemoryManagerVec &objectMemManager, size_t threadIdx );
  
          /**
          @param threadIdx
              Thread index so we know at which point we should start at.
              Must be unique for each worker thread
          */
          void updateAllLodsThread( const UpdateLodRequest &request, size_t threadIdx );
  
          /** Low level culling, culls all objects against the given frustum active cameras. This
              includes checking visibility flags (both scene and viewport's)
              @See MovableObject::cullFrustum
          @param request
              Fully setup request. @See CullFrustumRequest.
          @param threadIdx
              Index to mVisibleObjects so we know which array we should start at.
              Must be unique for each worker thread
          */
          void cullFrustum( const CullFrustumRequest &request, size_t threadIdx );
  
          /** Builds a list of all lights that are visible by all queued cameras (this should be fed by
              Compositor). Then calls MovableObject::buildLightList with that list so that each
              MovableObject gets it's own sorted list of the closest lights.
          @remarks
              @See MovableObject::buildLightList()
          */
          void buildLightList();
  
          void buildLightListThread01( const BuildLightListRequest &buildLightListRequest,
                                       size_t threadIdx );
          void buildLightListThread02( size_t threadIdx );
  
      public:
          /** Constructor.
          */
          SceneManager( const String& instanceName, size_t numWorkerThreads );
  
          /** Default destructor.
          */
          virtual ~SceneManager();
  
  
          /** Mutex to protect the scene graph from simultaneous access from
              multiple threads.
          @remarks
              If you are updating the scene in a separate thread from the rendering
              thread, then you should lock this mutex before making any changes to 
              the scene graph - that means creating, modifying or deleting a
              scene node, or attaching / detaching objects. It is <b>your</b> 
              responsibility to take out this lock, the detail methods on the nodes
              will not do it for you (for the reasons discussed below).
          @par
              Note that locking this mutex will prevent the scene being rendered until 
              it is unlocked again. Therefore you should do this sparingly. Try
              to create any objects you need separately and fully prepare them
              before doing all your scene graph work in one go, thus keeping this
              lock for the shortest time possible.
          @note
              A single global lock is used rather than a per-node lock since 
              it keeps the number of locks required during rendering down to a 
              minimum. Obtaining a lock, even if there is no contention, is not free
              so for performance it is good to do it as little as possible. 
              Since modifying the scene in a separate thread is a fairly
              rare occurrence (relative to rendering), it is better to keep the 
              locking required during rendering lower than to make update locks
              more granular.
          */
          OGRE_MUTEX(sceneGraphMutex);
  
          /** Return the instance name of this SceneManager. */
          const String& getName(void) const { return mName; }
  
          /** Retrieve the type name of this scene manager.
          @remarks
              This method has to be implemented by subclasses. It should
              return the type name of this SceneManager which agrees with 
              the type name of the SceneManagerFactory which created it.
          */
          virtual const String& getTypeName(void) const = 0;
  
          size_t getNumWorkerThreads() const                          { return mNumWorkerThreads; }
  
          /// Finds all the movable objects with the type and name passed as parameters.
          virtual MovableObjectVec findMovableObjects( const String& type, const String& name );
  
          /** Creates a camera to be managed by this scene manager.
              @remarks
                  This camera is automatically added to the scene by being attached to the Root
                  Scene Node before returning. If you want to use your own SceneNode for this
                  camera, you'll have to detach it first
                  (can be done via camera->detachFromParent();)
              @param name
                  Name to give the new camera. Must be unique.
              @param notShadowCaster
                  True if this camera should be considered when creating the global light list
                  of culled lights against all cameras. For example, cameras used for
                  shadow mapping shouldn't be taken into account (set to false)
              @param forCubemapping
                  True this camera will be used at least once in one of its passes as a cubemap
                  (thus having to change the orientation but not position mid-rendering)
          */
          virtual Camera* createCamera(const String& name, bool notShadowCaster=true, bool forCubemapping=false);
  
          /** Finds the camera with the given name. Throws if not found.
          @param name
              Hash of the name of the camera to find
          @return
              Camera pointer
          */
          virtual Camera* findCamera( IdString name ) const;
  
          /** Finds the camera with the given name. Returns null pointer if not found.
          @param name
              Hash of the name of the camera to find
          @return
              Camera pointer. Null if not found.
          */
          virtual Camera* findCameraNoThrow( IdString name ) const;
  
          /** Removes a camera from the scene.
              @remarks
                  This method removes a previously added camera from the scene.
                  The camera is deleted so the caller must ensure no references
                  to it's previous instance (e.g. in a SceneNode) are used.
              @param cam
                  Pointer to the camera to remove
          */
          virtual void destroyCamera(Camera *cam);
  
          /** Removes (and destroys) all cameras from the scene.
              @remarks
                  Some cameras are internal created to dealing with texture shadow,
                  or compositor nodes. They aren't supposed to be destroyed outside.
                  So, while you are using texture shadow, don't call this method.
          */
          virtual void destroyAllCameras(void);
  
          /// See Camera::setLightCullingVisibility
          void _setLightCullingVisibility( Camera *camera, bool collectLights, bool isCubemap );
  
          /** Creates a light for use in the scene.
              @remarks
                  The direction and position of a light is managed via
                  the scene node it is attached to. Make sure that you have
                  attached the light to a scene node (SceneNode::attachObject)
                  *before* calling Light::setDirection or Light::setPosition.
          */
          virtual Light* createLight();
  
          /// Clears temporary buffers and other data that needs to live every frame.
          void clearFrameData(void);
  
          const LightListInfo& getGlobalLightList(void) const { return mGlobalLightList; }
  
          /** Retrieve a set of clipping planes for a given light. 
          */
          virtual const PlaneList& getLightClippingPlanes(const Light* l);
  
          /** Retrieve a scissor rectangle for a given light and camera. 
          */
          virtual const RealRect& getLightScissorRect(const Light* l, const Camera* cam);
  
          /** Removes the light from the scene and destroys it based on a pointer.
              @remarks
                  Any pointers held to this light after calling this method will be invalid.
          */
          virtual void destroyLight(Light* light);
          /** Removes and destroys all lights in the scene.
          */
          virtual void destroyAllLights(void);
  
          /// Don't call this function directly. @see TagPoint::createChildTagPoint
          virtual TagPoint* _createTagPoint( SceneNode *parent, NodeMemoryManager *nodeMemoryManager );
  
          /// Creates a TagPoint that can be used like a SceneNode, or be used to be
          /// attached to a Bone. @see Bone::addTagPoint
          virtual TagPoint* createTagPoint(void);
  
          /** @see createSceneNode. This functions exists to satisfy @see SceneNode::createChildImpl
              Don't call this function directly
              @par
                  Parent to the scene node we're creating.
          */
          virtual SceneNode* _createSceneNode( SceneNode *parent, NodeMemoryManager *nodeMemoryManager );
  
          /** Creates an instance of a SceneNode.
              @remarks
                  Note that this does not add the SceneNode to the scene hierarchy.
                  This method is for convenience, since it allows an instance to
                  be created for which the SceneManager is responsible for
                  allocating and releasing memory, which is convenient in complex
                  scenes.
              @par
                  To include the returned SceneNode in the scene, use the addChild
                  method of the SceneNode which is to be it's parent.
              @par
                  Note that this method takes no parameters, and the node created is unnamed (it is
                  actually given a generated name, which you can retrieve if you want).
                  If you wish to create a node with a specific name, call the alternative method
                  which takes a name parameter.
              @params sceneType
                  Dynamic if this node is to be updated frequently. Static if you don't plan to be
                  updating this node in a long time (performance optimization).
          */
          virtual SceneNode* createSceneNode( SceneMemoryMgrTypes sceneType = SCENE_DYNAMIC );
  
          /** Destroys a SceneNode.
          @remarks
              This allows you to physically delete an individual SceneNode if you want to.
              Note that this is not normally recommended, it's better to allow SceneManager
              to delete the nodes when the scene is cleared.
          */
          virtual void destroySceneNode(SceneNode* sn);
  
          /** Sets a sky, to use a particular material based on SkyMethod
          @remarks
              You can control the order in which the sky appears (for best performance render
              the sky LAST i.e. after all opaque objects, but before transparent objects).
  
              You can control the order of the sky and its visibility flags by calling:
              @code
                  Rectangle2D *sky = sceneManager->getSky()
                  sky->setRenderQueueGroup( rqId )
                  sky->setRenderQueueSubGroup( rqSubGroupId )
                  sky->setVisibilityFlags( mask )
              @endcode
          @param bEnabled
          @param skyMethod
          @param texture
          */
          void setSky( bool bEnabled, SkyMethod skyMethod, TextureGpu *texture );
          void setSky( bool bEnabled, SkyMethod skyMethod, const String &texName,
                       const String &resourceGroup );
  
          Rectangle2D* getSky(void)                       { return mSky; }
          bool isSkyEnabled(void) const                   { return mSky != 0; }
          SkyMethod getSkyMethod(void) const              { return mSkyMethod; }
          MaterialPtr getSkyMaterial(void)                { return mSkyMaterial; }
  
          /** Draws a Radial Density Mask to lower the quality around the edges in VR
          @remarks
              You can control the order in which this RDM appears (to actually work as an optimization
              it must be the first thing being rendered!) and its visibility flags by calling:
              @code
                  RadialDensityMask *rdm = sceneManager->getRadialDensityMask()
                  rdm->getRectangle()->setRenderQueueGroup( rqId )
                  rdm->getRectangle()->setRenderQueueSubGroup( rqSubGroupId )
                  rdm->getRectangle()->setVisibilityFlags( mask )
              @endcode
          @param bEnabled
          @param radius
              Three sets of radiuses in clip space (i.e. in range [0; 1]) around each eye's center
                  All pixels inside radius[0] are rendered at full rate
                  All pixels between radius[0] & radius[1] are masked at half rate
                  All pixels between radius[1] & radius[2] are masked at quarter rate
                  All pixels beyond radius[2] are masked at 1/16th rate
          */
          void setRadialDensityMask( bool bEnabled, const float radius[3] );
          RadialDensityMask* getRadialDensityMask(void) const     { return mRadialDensityMask; }
  
          /** Gets the SceneNode at the root of the scene hierarchy.
              @remarks
                  The entire scene is held as a hierarchy of nodes, which
                  allows things like relative transforms, general changes in
                  rendering state etc (See the SceneNode class for more info).
                  In this basic SceneManager class, the application using
                  Ogre is free to structure this hierarchy however it likes,
                  since it has no real significance apart from making transforms
                  relative to each node (more specialised subclasses will
                  provide utility methods for building specific node structures
                  e.g. loading a BSP tree).
              @par
                  However, in all cases there is only ever one root node of
                  the hierarchy, and this method returns a pointer to it.
                  There is actually an extra Root Node so that static
                  objects can be attached to it. Note however, static nodes
                  can be children of a dynamic root node.
          */
          SceneNode* getRootSceneNode( SceneMemoryMgrTypes sceneType = SCENE_DYNAMIC );
  
          /// Unlike mNodeMemoryManager->_getDummyNode(), this dummy node is fully allocated,
          /// which makes it possible to actually attach objects to this dummy, while
          /// we guarantee the dummy won't change its transform.
          SceneNode* getDummySceneNode(void) const        { return mSceneDummy; }
  
          /** Retrieves a SceneNode based on it's ID from the scene graph.
          @remarks
              @note Returns null if the ID does not exist
              @note It is a linear search O(N), retrieves the first node found
              with that name (it's not unique)
          */
          virtual_l1 SceneNode* getSceneNode( IdType id );
          virtual_l1 const SceneNode* getSceneNode( IdType id ) const;
  
          /// Finds all the scene nodes with the name passed as parameter.
          virtual_l1 SceneNodeList findSceneNodes( const String& name ) const;
  
          /** Node listeners need to be registered with us so that they can be successfully called
              when calling updateAllTransforms. @See updateAllTransforms
          */
          virtual void registerSceneNodeListener( SceneNode *sceneNode );
  
          /** Unregisters a registered node for listening. @See registerSceneNodeListener
          */
          virtual void unregisterSceneNodeListener( SceneNode *sceneNode );
  
          /// Returns the RenderQueue.
          RenderQueue* getRenderQueue(void) const             { return mRenderQueue; }
  
          /** Enables or disables the Forward3D implementation for using many non-shadowed
              lights in the scene.
              See the Forward3D sample for more information.
          @remarks
              The Hlms implementation must support this feature in order to work.
              Calling this function can recreate resources (even if called multiple
              times with the same exact paramters). Don't do it often.
          @param bEnable
              True to enable it. False to disable it.
          @param width
              The width of the view-space grid. Recommended value is 4 unless
              numSlices is very small.
          @param height
              The height of the view-space grid. Recommended value is 4 unless
              numSlices is very small.
          @param numSlices
              The number of slices. Each additional slice consumes much more memory.
              The width and height is doubled on each slice. It's like mipmapping
              but on reverse.
          @param lightsPerCell
              The maximum number of lights a cell in the grid can hold.
          @param decalsPerCell
              Maximum number of decals a cell in the grid can hold. 0 to disable decals.
          @param minDistance
              Bias towards the camera for grid.
          @param maxDistance
              How far the grid array can go.
          */
          void setForward3D( bool bEnable, uint32 width, uint32 height, uint32 numSlices,
                             uint32 lightsPerCell, float minDistance, float maxDistance );
  
          void setForwardClustered( bool bEnable, uint32 width, uint32 height, uint32 numSlices,
                                    uint32 lightsPerCell, uint32 decalsPerCell, uint32 cubemapProbesPerCel,
                                    float minDistance, float maxDistance );
  
          /** Enables or disables the legace 1.9 way of building light lists which can be 
              used by HlmsLowLevel materials.
              This light list can be turned on regardless of any Forward* mode but it 
              consumes a lot of performance and is only used by HlmsLowLevel materials 
              that need ligting.
          */
          void setBuildLegacyLightList( bool bEnable );
  
          ForwardPlusBase* getForwardPlus(void)                       { return mForwardPlusSystem; }
          ForwardPlusBase* _getActivePassForwardPlus(void)            { return mForwardPlusImpl; }
  
          /** Sets the decal texture for diffuse. Should be a RGBA8 or similar colour format.
          @remarks
              If the emissive texture (see SceneManager::setDecalsEmissive) is the same as
              the diffuse, Hlms can perform a performance optimization and use fewer texture
              slots.
  
              You still need to enable a Forward+ solution that supports decals, such as
              SceneManager::setForwardClusted; otherwise decals won't be rendered.
          @param tex
              Null pointer to disable diffuse texture for all decals, globablly.
          */
          void setDecalsDiffuse( TextureGpu *tex );
          /** Sets the decal texture normal maps. Should be RG8_SNORM or BC5_SNORM.
  
              @see    SceneManager::setDecalsDiffuse
          @param tex
              Null pointer to disable normal map textures for all decals, globally.
          */
          void setDecalsNormals( TextureGpu *tex );
          /// See SceneManager::setDecalsDiffuse. Setting this texture to the same as diffuse
          /// incurs in a performance optimization.
          void setDecalsEmissive( TextureGpu *tex );
  
          TextureGpu* getDecalsDiffuse(void) const                    { return mDecalsDiffuseTex; }
          TextureGpu* getDecalsNormals(void) const                    { return mDecalsNormalsTex; }
          TextureGpu* getDecalsEmissive(void) const                   { return mDecalsEmissiveTex; }
          bool isDecalsDiffuseEmissiveMerged(void) const;
  
          /// For internal use.
          /// @see CompositorPassSceneDef::mEnableForwardPlus
          void _setForwardPlusEnabledInPass( bool bEnable );
  
          /// For internal use.
          /// @see CompositorPassSceneDef::mPrePassMode
          void _setPrePassMode( PrePassMode mode, const TextureGpuVec &prepassTextures,
                                TextureGpu *prepassDepthTexture, TextureGpu *ssrTexture );
          void _setRefractions( TextureGpu *depthTextureNoMsaa, TextureGpu *refractionsTexture );
          PrePassMode getCurrentPrePassMode(void) const               { return mPrePassMode; }
          const TextureGpuVec& getCurrentPrePassTextures(void) const  { return mPrePassTextures; }
          TextureGpu* getCurrentPrePassDepthTexture(void) const       { return mPrePassDepthTexture; }
          TextureGpu* getCurrentSsrTexture(void) const                { return mSsrTexture; }
          TextureGpu* getCurrentPassDepthTextureNoMsaa(void) const	{ return mPassDepthTextureNoMsaa; }
          TextureGpu* getCurrentRefractionsTexture(void) const        { return mRefractionsTexture; }
  
  
  
          NodeMemoryManager& _getNodeMemoryManager(SceneMemoryMgrTypes sceneType)
                                                                  { return mNodeMemoryManager[sceneType]; }
          NodeMemoryManager& _getTagPointNodeMemoryManager(void)  { return mTagPointNodeMemoryManager; }
  
          /** Retrieves the main entity memory manager.
          @remarks
              Some Scene Managers may have more than one memory manager (e.g. one per octant in an
              Octree implementation). At end of scene graph update the scene manager may move
              the object created with the main memory manager into another another one.
          */
          ObjectMemoryManager& _getEntityMemoryManager(SceneMemoryMgrTypes sceneType)
                                                              { return mEntityMemoryManager[sceneType]; }
          ObjectMemoryManager& _getLightMemoryManager(void)
                                                              { return mLightMemoryManager; }
  
          /// @copydoc ArrayMemoryManager::defragment
          void defragmentMemoryPools(void);
  
          /// @copydoc ArrayMemoryManager::shrinkToFit
          void shrinkToFitMemoryPools(void);
  
          /** Create an Item (instance of a discrete mesh).
              @param
                  meshName The name of the Mesh it is to be based on (e.g. 'knot.oof'). The
                  mesh will be loaded if it is not already.
          */
          virtual Item* createItem( const String& meshName,
                                    const String& groupName = ResourceGroupManager::AUTODETECT_RESOURCE_GROUP_NAME,
                                    SceneMemoryMgrTypes sceneType = SCENE_DYNAMIC );
  
          /** Create an Item (instance of a discrete mesh).
              @param
                  pMesh The pointer to the Mesh it is to be based on.
          */
          virtual Item* createItem( const MeshPtr& pMesh,
                                    SceneMemoryMgrTypes sceneType = SCENE_DYNAMIC );
  
          /// Removes & destroys an Item from the SceneManager.
          virtual void destroyItem( Item *item );
  
          /// Removes & destroys all Items.
          virtual void destroyAllItems(void);
  
          /// Create an WireAabb
          virtual WireAabb* createWireAabb(void);
  
          /// Removes & destroys an WireAabb from the SceneManager.
          virtual void destroyWireAabb( WireAabb *wireAabb );
  
          /// Removes & destroys all WireAabbs.
          virtual void destroyAllWireAabbs(void);
  
          void _addWireAabb( WireAabb *wireAabb );
          void _removeWireAabb( WireAabb *wireAabb );
  
          /** Create an Entity (instance of a discrete mesh).
              @param
                  meshName The name of the Mesh it is to be based on (e.g. 'knot.oof'). The
                  mesh will be loaded if it is not already.
          */
          virtual v1::Entity* createEntity( const String& meshName,
                                            const String& groupName = ResourceGroupManager::AUTODETECT_RESOURCE_GROUP_NAME,
                                            SceneMemoryMgrTypes sceneType = SCENE_DYNAMIC );
  
          /** Create an Entity (instance of a discrete mesh).
              @param
                  pMesh The pointer to the Mesh it is to be based on.
          */
          virtual v1::Entity* createEntity( const v1::MeshPtr& pMesh,
                                            SceneMemoryMgrTypes sceneType = SCENE_DYNAMIC );
  
          /** Prefab shapes available without loading a model.
              @note
                  Minimal implementation at present.
              @todo
                  Add more prefabs (teapots, teapots!!!)
          */
          enum PrefabType {
              PT_PLANE,
              PT_CUBE,
              PT_SPHERE
          };
  
          /** Create an Entity (instance of a discrete mesh) from a range of prefab shapes
              @param ptype The prefab type.
          */
          virtual v1::Entity* createEntity( PrefabType ptype,
                                            SceneMemoryMgrTypes sceneType = SCENE_DYNAMIC );
  
          /** Removes & destroys an Entity from the SceneManager.
              @warning
                  Must only be done if the Entity is not attached
                  to a SceneNode. It may be safer to wait to clear the whole
                  scene if you are unsure use clearScene.
              @see
                  SceneManager::clearScene
          */
          virtual void destroyEntity(v1::Entity* ent);
  
          /** Removes & destroys all Entities.
              @warning
                  Again, use caution since no Entity must be referred to
                  elsewhere e.g. attached to a SceneNode otherwise a crash
                  is likely. Use clearScene if you are unsure (it clears SceneNode
                  entries too.)
              @see
                  SceneManager::clearScene
          */
          virtual void destroyAllEntities(void);
  
          virtual Decal* createDecal( SceneMemoryMgrTypes sceneType = SCENE_DYNAMIC );
          virtual void destroyDecal( Decal *decal );
          virtual void destroyAllDecals(void);
  
          virtual InternalCubemapProbe* _createCubemapProbe( SceneMemoryMgrTypes sceneType );
          virtual void _destroyCubemapProbe( InternalCubemapProbe *probe );
          virtual void _destroyAllCubemapProbes(void);
  
          /** Creates a 2D rectangle that can be displayed for screen space effects or
              showing a basic GUI.
              Notice that due to engine's requirements, you need to attach this object
              to a scene node in order to be rendered correctly.
          @par
              You can use the Root scene node. However if you're planning on also using
              setRelativeOrigin, beware that this would break the permanent setting and
              you should then use a dummy scene node for your rectangles.
          @remarks
              The Rectangle2D will request to use identity view and projection matrices,
              but only low level materials will honour that request. PBS shaders will
              ignore it (thus the rectangle will be drawn in 3D space) and other Hlms
              types may work differently and you'll have to check its documentation.
          @param sceneType
              Whether you will be moving the Rectangle2D's scene node around. Unless you're
              planning to use this Rectangle2D for 3D purposes, it is highly recomended that
              you use SCENE_STATIC (you can safely use SCENE_STATIC and change
              Rectangle2D::setCorners and Rectangle2D::setNormal every frame).
          @return
              The Rectangle2D.
          */
          virtual Rectangle2D* createRectangle2D( SceneMemoryMgrTypes sceneType = SCENE_STATIC );
  
          /** Removes & destroys an Entity from the SceneManager.
          @warning
              It may be safer to wait to clear the whole scene if you are unsure use clearScene.
              @see SceneManager::clearScene
          */
          virtual void destroyRectangle2D( Rectangle2D *rect );
  
          /** Removes & destroys all Rectangle2D.
              @warning
                  Again, use caution since no Rectangle2D must be referred to
                  elsewhere otherwise a crash is likely. Use clearScene if you
                  are unsure (it clears SceneNode entries too.)
              @see
                  SceneManager::clearScene
          */
          virtual void destroyAllRectangle2D(void);
  
          /** Used by Compositor, tells of which compositor textures active,
              so Materials can access them. If MRT, there could be more than one
          @param name
              Name of the texture(s) as referenced in the compositor
              (may not be the texture's real name in case it's just one)
          @param tex
              The actual texture(s) associated with that name
          */
          void _addCompositorTexture( IdString name, TextureGpu *tex );
  
          /// @see CompositorPassDef::mExposedTextures for the textures that are available
          /// in the current compositor pass. The compositor script keyword is "expose".
          const CompositorTextureVec& getCompositorTextures(void) const   { return mCompositorTextures; }
  
          /// Gets the number of currently active compositor textures
          size_t getNumCompositorTextures(void) const         { return mCompositorTextures.size(); }
  
          /// Removes all compositor textures from 'from' to end.
          void _removeCompositorTextures( size_t from );
  
          /// Creates an instance of a skeleton based on the given definition.
          SkeletonInstance* createSkeletonInstance( const SkeletonDef *skeletonDef );
          /// Destroys an instance of a skeleton created with @createSkeletonInstance.
          void destroySkeletonInstance( SkeletonInstance *skeletonInstance );
          /// Removes a skeleton definition from its memory manager.
          void _removeSkeletonDef( const SkeletonDef *skeletonDef );
  
          /** Create a ManualObject, an object which you populate with geometry
              manually through a GL immediate-mode style interface.
          */
          virtual ManualObject* createManualObject( SceneMemoryMgrTypes sceneType = SCENE_DYNAMIC );
          /** Removes & destroys a ManualObject from the SceneManager.
          */
          virtual void destroyManualObject(ManualObject* obj);
          /** Removes & destroys all ManualObjects from the SceneManager.
          */
          virtual void destroyAllManualObjects(void);
          /** Create a BillboardChain, an object which you can use to render
              a linked chain of billboards.
          */
          virtual v1::BillboardChain* createBillboardChain();
          /** Removes & destroys a BillboardChain from the SceneManager.
          */
          virtual void destroyBillboardChain(v1::BillboardChain* obj);
          /** Removes & destroys all BillboardChains from the SceneManager.
          */
          virtual void destroyAllBillboardChains(void);       
          /** Create a RibbonTrail, an object which you can use to render
              a linked chain of billboards which follows one or more nodes.
          */
          virtual v1::RibbonTrail* createRibbonTrail();
          /** Removes & destroys a RibbonTrail from the SceneManager.
          */
          virtual void destroyRibbonTrail(v1::RibbonTrail* obj);
          /** Removes & destroys all RibbonTrails from the SceneManager.
          */
          virtual void destroyAllRibbonTrails(void);      
  
          /** Creates a particle system based on a template.
          @remarks
              This method creates a new ParticleSystem instance based on the named template
              (defined through ParticleSystemManager::createTemplate) and returns a 
              pointer to the caller. The caller should not delete this object, it will be freed at system shutdown, 
              or can be released earlier using the destroyParticleSystem method.
          @par
              Each system created from a template takes the template's settings at the time of creation, 
              but is completely separate from the template from there on. 
          @par
              Creating a particle system does not make it a part of the scene. As with other MovableObject
              subclasses, a ParticleSystem is not rendered until it is attached to a SceneNode. 
          @par
              This is probably the more useful particle system creation method since it does not require manual
              setup of the system. Note that the initial quota is based on the template but may be changed later.
          @param 
              templateName The name of the template to base the new instance on.
          */
          virtual ParticleSystem* createParticleSystem( const String& templateName );
          /** Create a blank particle system.
          @remarks
              This method creates a new, blank ParticleSystem instance and returns a pointer to it.
              The caller should not delete this object, it will be freed at system shutdown, or can
              be released earlier using the destroyParticleSystem method.
          @par
              The instance returned from this method won't actually do anything because on creation a
              particle system has no emitters. The caller should manipulate the instance through it's 
              ParticleSystem methods to actually create a real particle effect. 
          @par
              Creating a particle system does not make it a part of the scene. As with other MovableObject
              subclasses, a ParticleSystem is not rendered until it is attached to a SceneNode. 
          @param 
              quota The maximum number of particles to allow in this system. 
          @param
              resourceGroup The resource group which will be used to load dependent resources
          */
          virtual ParticleSystem* createParticleSystem( size_t quota = 500, 
              const String& resourceGroup = ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME );
  
          /** Removes & destroys a ParticleSystem from the SceneManager.
          */
          virtual void destroyParticleSystem(ParticleSystem* obj);
          /** Removes & destroys all ParticleSystems from the SceneManager.
          */
          virtual void destroyAllParticleSystems(void);       
  
          /** Empties the entire scene, inluding all SceneNodes, Entities, Lights, 
              BillboardSets etc. Cameras are not deleted at this stage since
              they are still referenced by viewports, which are not destroyed during
              this process.
          @remarks
              When an indestructible SceneNode has a destructible parent, the parent
              will be destroyed and thus the former SceneNode will be parent-less,
              i.e. be at the same level as root. Note that parent-less SceneNodes can
              still render to the scene (this behavior is different from Ogre 1.x)
          @param deleteIndestructibleToo
              If a node is marked as indestructible, it won't be deleted unless
              deleteIndestructibleToo is marked as true.
              Note that some Ogre compoenents mark some of their objects as internal to
              prevent them from becoming dangling pointers.
  
              If you don't know what to put here, set it to false.
          @param reattachCameras
              When true, all Cameras that have no parent node after clearing
              will be reattached to the root node.
          */
          virtual void clearScene( bool deleteIndestructibleToo, bool reattachCameras=true );
  
          /** Sets the ambient light level to be used for the scene.
          @remarks
              Ambient lighting is a cheap fake to compensate the lack of global illumination.
              Hemisphere ambient lighting will set the final ambient light to the following
              formula:
                  float w = dot( objNormal, hemisphereDir ) * 0.5 + 0.5;
                  finalAmbient = lerp( lowerHemisphere, upperHemisphere, w );
  
              Setting upperHemisphere = lowerHemisphere is effectively a traditional
              fixed-colour ambient light.
          @par
              Tip: Set the upperHemisphere to a cold colour (e.g. blueish sky) and lowerHemisphere
              to a warm colour (e.g. sun-yellowish, orange) and the hemisphereDir in the opposite
              direction of your main directional light for a convincing look.
          @par
              By default the ambient light in the scene is ColourValue::Black, i.e. no ambient light.
              This means that any objects rendered with a Material which has lighting enabled
              (see Material::setLightingEnabled) will not be visible unless you have some dynamic
              lights in your scene.
          @par
              For compatibility reasons with legacy (e.g. low level materials) upperHemisphere's
              colour is the old ambient colour from 1.x
  
          @param upperHemisphere
              Ambient colour when the surface normal is close to hemisphereDir
          @param lowerHemisphere
              Ambient colour when the surface normal is pointing away from hemisphereDir
          @param hemisphereDir
              Hemisphere's direction reference to compare the surface normal to.
              The internal vector will be normalized.
          @param envmapScale
              Global scale to apply to all environment maps (for relevant Hlms implementations,
              like PBS). The value will be stored in upperHemisphere.a
              Use 1.0 to disable.
          @param envFeatures
              Bitmask. See SceneManager::EnvFeatures
          */
          void setAmbientLight( const ColourValue& upperHemisphere, const ColourValue& lowerHemisphere,
                                const Vector3 &hemisphereDir, Real envmapScale = 1.0f,
                                uint32 envFeatures=0xffffffff );
  
          void setSphericalHarmonics( Vector3 ambientSphericalHarmonics[9] );
  
          /** Returns the ambient light level to be used for the scene.
          */
          const ColourValue& getAmbientLightUpperHemisphere(void) const   { return mAmbientLight[0]; }
          const ColourValue& getAmbientLightLowerHemisphere(void) const   { return mAmbientLight[1]; }
          const Vector3& getAmbientLightHemisphereDir(void) const { return mAmbientLightHemisphereDir; }
          uint32 getEnvFeatures(void) const                       { return mEnvFeatures; }
          const float* getSphericalHarmonics(void) const          { return mAmbientSphericalHarmonics; }
  
          /** Sets the source of the 'world' geometry, i.e. the large, mainly static geometry
              making up the world e.g. rooms, landscape etc.
              This function can be called before setWorldGeometry in a background thread, do to
              some slow tasks (e.g. IO) that do not involve the backend render system.
              @remarks
                  Depending on the type of SceneManager (subclasses will be specialised
                  for particular world geometry types) you have requested via the Root or
                  SceneManagerEnumerator classes, you can pass a filename to this method and it
                  will attempt to load the world-level geometry for use. If you try to load
                  an inappropriate type of world data an exception will be thrown. The default
                  SceneManager cannot handle any sort of world geometry and so will always
                  throw an exception. However subclasses like BspSceneManager can load
                  particular types of world geometry e.g. "q3dm1.bsp".
  
          */
          virtual void prepareWorldGeometry(const String& filename);
  
          /** Sets the source of the 'world' geometry, i.e. the large, mainly 
              static geometry making up the world e.g. rooms, landscape etc.
              This function can be called before setWorldGeometry in a background thread, do to
              some slow tasks (e.g. IO) that do not involve the backend render system.
              @remarks
                  Depending on the type of SceneManager (subclasses will be 
                  specialised for particular world geometry types) you have 
                  requested via the Root or SceneManagerEnumerator classes, you 
                  can pass a stream to this method and it will attempt to load 
                  the world-level geometry for use. If the manager can only 
                  handle one input format the typeName parameter is not required.
                  The stream passed will be read (and it's state updated). 
              @param stream Data stream containing data to load
              @param typeName String identifying the type of world geometry
                  contained in the stream - not required if this manager only 
                  supports one type of world geometry.
          */
          virtual void prepareWorldGeometry(DataStreamPtr& stream, 
              const String& typeName = BLANKSTRING);
  
          /** Sets the source of the 'world' geometry, i.e. the large, mainly static geometry
              making up the world e.g. rooms, landscape etc.
              @remarks
                  Depending on the type of SceneManager (subclasses will be specialised
                  for particular world geometry types) you have requested via the Root or
                  SceneManagerEnumerator classes, you can pass a filename to this method and it
                  will attempt to load the world-level geometry for use. If you try to load
                  an inappropriate type of world data an exception will be thrown. The default
                  SceneManager cannot handle any sort of world geometry and so will always
                  throw an exception. However subclasses like BspSceneManager can load
                  particular types of world geometry e.g. "q3dm1.bsp".
          */
          virtual void setWorldGeometry(const String& filename);
  
          /** Sets the source of the 'world' geometry, i.e. the large, mainly 
              static geometry making up the world e.g. rooms, landscape etc.
              @remarks
                  Depending on the type of SceneManager (subclasses will be 
                  specialised for particular world geometry types) you have 
                  requested via the Root or SceneManagerEnumerator classes, you 
                  can pass a stream to this method and it will attempt to load 
                  the world-level geometry for use. If the manager can only 
                  handle one input format the typeName parameter is not required.
                  The stream passed will be read (and it's state updated). 
              @param stream Data stream containing data to load
              @param typeName String identifying the type of world geometry
                  contained in the stream - not required if this manager only 
                  supports one type of world geometry.
          */
          virtual void setWorldGeometry(DataStreamPtr& stream, 
              const String& typeName = BLANKSTRING);
  
          /** Estimate the number of loading stages required to load the named
              world geometry. 
          @remarks
              This method should be overridden by SceneManagers that provide
              custom world geometry that can take some time to load. They should
              return from this method a count of the number of stages of progress
              they can report on whilst loading. During real loading (setWorldGeometry),
              they should call ResourceGroupManager::_notifyWorldGeometryProgress exactly
              that number of times when loading the geometry for real.
          @note 
              The default is to return 0, ie to not report progress. 
          */
          virtual size_t estimateWorldGeometry(const String& filename)
          { (void)filename; return 0; }
  
          /** Estimate the number of loading stages required to load the named
              world geometry. 
          @remarks
              Operates just like the version of this method which takes a
              filename, but operates on a stream instead. Note that since the
              stream is updated, you'll need to reset the stream or reopen it
              when it comes to loading it for real.
          @param stream Data stream containing data to load
          @param typeName String identifying the type of world geometry
              contained in the stream - not required if this manager only 
              supports one type of world geometry.
          */      
          virtual size_t estimateWorldGeometry(DataStreamPtr& stream, 
              const String& typeName = BLANKSTRING)
          { (void)stream; (void)typeName; return 0; }
  
          /** Asks the SceneManager to provide a suggested viewpoint from which the scene should be viewed.
              @remarks
                  Typically this method returns the origin unless a) world geometry has been loaded using
                  SceneManager::setWorldGeometry and b) that world geometry has suggested 'start' points.
                  If there is more than one viewpoint which the scene manager can suggest, it will always suggest
                  the first one unless the random parameter is true.
              @param
                  random If true, and there is more than one possible suggestion, a random one will be used. If false
                  the same one will always be suggested.
              @return
                  On success, true is returned.
              @par
                  On failure, false is returned.
          */
          virtual ViewPoint getSuggestedViewpoint(bool random = false);
  
          /** Method for setting a specific option of the Scene Manager. These options are usually
              specific for a certain implemntation of the Scene Manager class, and may (and probably
              will) not exist across different implementations.
              @param
                  strKey The name of the option to set
              @param
                  pValue A pointer to the value - the size should be calculated by the scene manager
                  based on the key
              @return
                  On success, true is returned.
              @par
                  On failure, false is returned.
          */
          virtual bool setOption( const String& strKey, const void* pValue )
          { (void)strKey; (void)pValue; return false; }
  
          /** Method for getting the value of an implementation-specific Scene Manager option.
              @param
                  strKey The name of the option
              @param
                  pDestValue A pointer to a memory location where the value will
                  be copied. Currently, the memory will be allocated by the
                  scene manager, but this may change
              @return
                  On success, true is returned and pDestValue points to the value of the given
                  option.
              @par
                  On failure, false is returned and pDestValue is set to NULL.
          */
          virtual bool getOption( const String& strKey, void* pDestValue )
          { (void)strKey; (void)pDestValue; return false; }
  
          /** Method for verifying whether the scene manager has an implementation-specific
              option.
              @param
                  strKey The name of the option to check for.
              @return
                  If the scene manager contains the given option, true is returned.
              @remarks
                  If it does not, false is returned.
          */
          virtual bool hasOption( const String& strKey ) const
          { (void)strKey; return false; }
  
          /** Method for getting all possible values for a specific option. When this list is too large
              (i.e. the option expects, for example, a float), the return value will be true, but the
              list will contain just one element whose size will be set to 0.
              Otherwise, the list will be filled with all the possible values the option can
              accept.
              @param
                  strKey The name of the option to get the values for.
              @param
                  refValueList A reference to a list that will be filled with the available values.
              @return
                  On success (the option exists), true is returned.
              @par
                  On failure, false is returned.
          */
          virtual bool getOptionValues( const String& strKey, StringVector& refValueList )
          { (void)strKey; (void)refValueList; return false; }
  
          /** Method for getting all the implementation-specific options of the scene manager.
              @param
                  refKeys A reference to a list that will be filled with all the available options.
              @return
                  On success, true is returned. On failure, false is returned.
          */
          virtual bool getOptionKeys( StringVector& refKeys )
          { (void)refKeys; return false; }
  
          /// @See mTmpVisibleObjects
          VisibleObjectsPerThreadArray& _getTmpVisibleObjectsList()           { return mTmpVisibleObjects; }
  
          /** Notifies that the given MovableObject is dirty (i.e. the AABBs have changed).
              Note that the parent SceneNodes of this/these objects are not updated and you will
              have to call @see notifyStaticDirty on the SceneNode if the position/rotation/scale
              have changed.
          */
          void notifyStaticAabbDirty( MovableObject *movableObject );
  
          /** Notifies that the given Node is dirty (i.e. the position, orientation and/or scale has
              changed). The call will cascade to all children of the input node.
          @remarks
              Implies a call to @see notifyStaticAabbDirty if the node or any of its children has
              a MovableObject attached.
          @par
              Calling notifyStaticDirty( getRootSceneNode( SCENE_STATIC ) ) should flush the entire
              static system. It might be slower, but it is useful when you're witnessing artifacts
              after making changes to the static environment and don't know for sure which objects
              need to be updated.
          */
          void notifyStaticDirty( Node *node );
  
          /** Updates all skeletal animations in the scene. This is typically called once
              per frame during render, but the user might want to manually call this function.
          @remarks
              mSkeletonAnimManagerCulledList must be set. @See updateAllTransforms remarks
          */
          void updateAllAnimations();
  
          /** Updates the derived transforms of all nodes in the scene. This is typically called once
              per frame during render, but the user may want to manually call this function.
          @remarks
              mEntitiesMemoryManagerUpdateList must be set. It contains multiple memory manager
              containing all objects to be updated (i.e. Entities & Lights are both MovableObjects
              but are kept separate)
              Don't call this function from another thread other than Ogre's main one (we use worker
              threads that may be in use for something else, and touching the sync barrier
              could deadlock in the best of cases).
          */
          void updateAllTransforms();
  
          /** Updates all TagPoints, both TagPoints that are children of bones, and TagPoints that
              are children of other TagPoints.
          @remarks
              mTagPointNodeMemoryManagerUpdateList must be set. @see updateAllTransforms remarks
          */
          void updateAllTagPoints(void);
  
          /** Updates the world aabbs from all entities in the scene. Ought to be called right after
              updateAllTransforms. @See updateAllTransforms
          @remarks
              @See MovableObject::updateAllBounds
              Don't call this function from another thread other than Ogre's main one (we use worker
              threads that may be in use for something else, and touching the sync barrier
              could deadlock in the best of cases).
          */
          void updateAllBounds( const ObjectMemoryManagerVec &objectMemManager );
  
          /** Updates the Lod values of all objects relative to the given camera.
          */
          void updateAllLods( const Camera *lodCamera, Real lodBias, uint8 firstRq, uint8 lastRq );
  
          /** Updates the scene: Perform high level culling, Node transforms and entity animations.
          */
          void updateSceneGraph();
  
          /** Internal method for applying animations to scene nodes.
          @remarks
              Uses the internally stored AnimationState objects to apply animation to SceneNodes.
          */
          virtual void _applySceneAnimations(void);
  
          /// Returns true if collection code was run. When false, you cannot
          /// trust the contents of _getTmpVisibleObjectsList to be empty
          bool _collectForwardPlusObjects( const Camera *camera );
  
          /** Performs the frustum culling that will later be needed by _renderPhase02
              @remarks
                  @See CompositorShadowNode to understand why rendering is split in two phases
              @param camera Pointer to a camera from whose viewpoint the scene is to
                  be rendered.
              @param vp The target viewport
              @param firstRq first render queue ID to render (gets clamped if too big)
              @param lastRq last render queue ID to render (gets clamped if too big)
          */
          virtual void _cullPhase01( Camera *cullCamera, Camera *renderCamera, const Camera *lodCamera,
                                     uint8 firstRq, uint8 lastRq, bool reuseCullData );
  
          /** Prompts the class to send its contents to the renderer.
              @remarks
                  This method prompts the scene manager to send the
                  contents of the scene it manages to the rendering
                  pipeline. You must have called _cullPhase01 before calling
                  this function.
                  Note that this method is not normally called directly by the
                  user application; it is called automatically by the Ogre
                  rendering loop.
              @param camera Pointer to a camera from whose viewpoint the scene is to
                  be rendered.
              @param lodCamera Pointer to a camera from whose LOD calculations will be
                  based upon. Can't be null; can be equal to @camera.
              @param vp The target viewport
              @param firstRq first render queue ID to render (gets clamped if too big)
              @param lastRq last render queue ID to render (gets clamped if too big)
              @param includeOverlays Whether or not overlay objects should be rendered
          */
          virtual void _renderPhase02( Camera* camera, const Camera* lodCamera,
                                       uint8 firstRq, uint8 lastRq, bool includeOverlays );
  
          void cullLights( Camera *camera, Light::LightTypes startType,
                           Light::LightTypes endType, LightArray &outLights );
  
          /// Called when the frame has fully ended (ALL passes have been executed to all RTTs)
          void _frameEnded(void);
  
          /** Notifies the scene manager of its destination render system
              @remarks
                  Called automatically by RenderSystem::addSceneManager
                  this method simply notifies the manager of the render
                  system to which its output must be directed.
              @param
                  sys Pointer to the RenderSystem subclass to be used as a render target.
          */
          virtual void _setDestinationRenderSystem(RenderSystem* sys);
  
          void _setCamerasInProgress(const CamerasInProgress& cameras)    { mCamerasInProgress = cameras; }
  
          /** Notifies the scene manager that hardware resources were lost
              @remarks
                  Called automatically by RenderSystem if hardware resources
                  were lost and can not be restored using some internal mechanism.
                  Among affected resources are manual meshes without loaders, 
                  manual textures without loaders, ManualObjects, etc.
          */
          virtual void _releaseManualHardwareResources();
  
          /** Notifies the scene manager that hardware resources should be restored
              @remarks
                  Called automatically by RenderSystem if hardware resources
                  were lost and can not be restored using some internal mechanism.
                  Among affected resources are manual meshes without loaders, 
                  manual textures without loaders, ManualObjects, etc.
          */
          virtual void _restoreManualHardwareResources();
  
          /** Sets the fogging mode applied to the scene.
              @remarks
                  This method sets up the scene-wide fogging effect. These settings
                  apply to all geometry rendered, UNLESS the material with which it
                  is rendered has it's own fog settings (see Material::setFog).
              @param
                  mode Set up the mode of fog as described in the FogMode
                  enum, or set to FOG_NONE to turn off.
              @param
                  colour The colour of the fog. Either set this to the same
                  as your viewport background colour, or to blend in with a
                  skydome or skybox.
              @param
                  expDensity The density of the fog in FOG_EXP or FOG_EXP2
                  mode, as a value between 0 and 1. The default is 0.001. 
              @param
                  linearStart Distance in world units at which linear fog starts to
                  encroach. Only applicable if mode is
                  FOG_LINEAR.
              @param
                  linearEnd Distance in world units at which linear fog becomes completely
                  opaque. Only applicable if mode is
                  FOG_LINEAR.
          */
          void setFog(
              FogMode mode = FOG_NONE, const ColourValue& colour = ColourValue::White,
              Real expDensity = 0.001, Real linearStart = 0.0, Real linearEnd = 1.0);
  
          /** Returns the fog mode for the scene.
          */
          virtual FogMode getFogMode(void) const;
  
          /** Returns the fog colour for the scene.
          */
          virtual const ColourValue& getFogColour(void) const;
  
          /** Returns the fog start distance for the scene.
          */
          virtual Real getFogStart(void) const;
  
          /** Returns the fog end distance for the scene.
          */
          virtual Real getFogEnd(void) const;
  
          /** Returns the fog density for the scene.
          */
          virtual Real getFogDensity(void) const;
  
  
          /** Creates a new BillboardSet for use with this scene manager.
              @remarks
                  This method creates a new BillboardSet which is registered with
                  the SceneManager. The SceneManager will destroy this object when
                  it shuts down or when the SceneManager::clearScene method is
                  called, so the caller does not have to worry about destroying
                  this object (in fact, it definitely should not do this).
              @par
                  See the BillboardSet documentations for full details of the
                  returned class.
              @param
                  poolSize The initial size of the pool of billboards (see BillboardSet for more information)
              @see
                  BillboardSet
          */
          virtual v1::BillboardSet* createBillboardSet(unsigned int poolSize = 20);
  
          /** Removes & destroys an BillboardSet from the SceneManager.
              @warning
                  Must only be done if the BillboardSet is not attached
                  to a SceneNode. It may be safer to wait to clear the whole
                  scene. If you are unsure, use clearScene.
          */
          virtual void destroyBillboardSet(v1::BillboardSet* set);
  
          /** Removes & destroys all BillboardSets.
          @warning
          Again, use caution since no BillboardSet must be referred to
          elsewhere e.g. attached to a SceneNode otherwise a crash
          is likely. Use clearScene if you are unsure (it clears SceneNode
          entries too.)
          @see
          SceneManager::clearScene
          */
          virtual void destroyAllBillboardSets(void);
  
          /** Tells the SceneManager whether it should render the SceneNodes which 
              make up the scene as well as the objects in the scene.
          @remarks
              This method is mainly for debugging purposes. If you set this to 'true',
              each node will be rendered as a set of 3 axes to allow you to easily see
              the orientation of the nodes.
          */
          virtual void setDisplaySceneNodes(bool display);
          /** Returns true if all scene nodes axis are to be displayed */
          virtual bool getDisplaySceneNodes(void) const {return mDisplayNodes;}
  
          /** Creates an animation which can be used to animate scene nodes.
          @remarks
              An animation is a collection of 'tracks' which over time change the position / orientation
              of Node objects. In this case, the animation will likely have tracks to modify the position
              / orientation of SceneNode objects, e.g. to make objects move along a path.
          @par
              You don't need to use an Animation object to move objects around - you can do it yourself
              using the methods of the Node in your FrameListener class. However, when you need relatively
              complex scripted animation, this is the class to use since it will interpolate between
              keyframes for you and generally make the whole process easier to manage.
          @par
              A single animation can affect multiple Node objects (each AnimationTrack affects a single Node).
              In addition, through animation blending a single Node can be affected by multiple animations,
              athough this is more useful when performing skeletal animation (see Skeleton::createAnimation).
          @par
              Note that whilst it uses the same classes, the animations created here are kept separate from the
              skeletal animations of meshes (each Skeleton owns those animations).
          @param name The name of the animation, must be unique within this SceneManager.
          @param length The total length of the animation.
          */
          virtual v1::Animation* createAnimation(const String& name, Real length);
  
          /** Looks up an Animation object previously created with createAnimation. 
          @note Throws an exception if the named instance does not exist
          */
          virtual v1::Animation* getAnimation(const String& name) const;
          /** Returns whether an animation with the given name exists.
          */
          virtual bool hasAnimation(const String& name) const;
  
          /** Destroys an Animation. 
          @remarks
              You should ensure that none of your code is referencing this animation objects since the 
              memory will be freed.
          */
          virtual void destroyAnimation(const String& name);
  
          /** Removes all animations created using this SceneManager. */
          virtual void destroyAllAnimations(void);
  
          /** Create an AnimationState object for managing application of animations.
          @remarks
              You can create Animation objects for animating SceneNode obejcts using the
              createAnimation method. However, in order to actually apply those animations
              you have to call methods on Node and Animation in a particular order (namely
              Node::resetToInitialState and Animation::apply). To make this easier and to
              help track the current time position of animations, the AnimationState object
              is provided.
              So if you don't want to control animation application manually, call this method,
              update the returned object as you like every frame and let SceneManager apply 
              the animation state for you.
          @par
              Remember, AnimationState objects are disabled by default at creation time. 
              Turn them on when you want them using their setEnabled method.
          @par
              Note that any SceneNode affected by this automatic animation will have it's state
              reset to it's initial position before application of the animation. Unless specifically
              modified using Node::setInitialState the Node assumes it's initial state is at the
              origin. If you want the base state of the SceneNode to be elsewhere, make your changes
              to the node using the standard transform methods, then call setInitialState to 
              'bake' this reference position into the node.
          @par
              If the target of your animation is to be a generic AnimableValue, you
              should ensure that it has a base value set (unlike nodes this has no
              default). @see AnimableValue::setAsBaseValue.
          @param animName The name of an animation created already with createAnimation.
          */
          virtual v1::AnimationState* createAnimationState(const String& animName);
  
          /** Retrieves animation state as previously created using createAnimationState. 
          @note Throws an exception if the named instance does not exist
          */
          virtual v1::AnimationState* getAnimationState(const String& animName) const;
          /** Returns whether an animation state with the given name exists.
          */
          virtual bool hasAnimationState(const String& name) const;
  
          /** Destroys an AnimationState. 
          @remarks
              You should ensure that none of your code is referencing this animation 
              state object since the memory will be freed.
          */
          virtual void destroyAnimationState(const String& name);
  
          /** Removes all animation states created using this SceneManager. */
          virtual void destroyAllAnimationStates(void);
  
          /** Registers a new RenderQueueListener which will be notified when render queues
              are processed.
          */
          virtual void addRenderQueueListener(RenderQueueListener* newListener);
  
          /** Removes a listener previously added with addRenderQueueListener. */
          virtual void removeRenderQueueListener(RenderQueueListener* delListener);
          
          /** Registers a new Render Object Listener which will be notified when rendering an object.     
          */
          virtual void addRenderObjectListener(RenderObjectListener* newListener);
          /** Removes a listener previously added with addRenderObjectListener. */
          virtual void removeRenderObjectListener(RenderObjectListener* delListener);
  
          /** Allows all bounding boxes of scene nodes to be displayed. */
          virtual void showBoundingBoxes(bool bShow);
  
          /** Returns if all bounding boxes of scene nodes are to be displayed */
          virtual bool getShowBoundingBoxes() const;
  
          /** Internal method for notifying the manager that a SceneNode is autotracking. */
  		virtual void _addAutotrackingSceneNode( SceneNode* source, SceneNode* target,
  												const Vector3 &offset, const Vector3 &localDirection );
  		virtual void _removeAutotrackingSceneNode( SceneNode* source );
  
          
          /** Creates an AxisAlignedBoxSceneQuery for this scene manager. 
          @remarks
              This method creates a new instance of a query object for this scene manager, 
              for an axis aligned box region. See SceneQuery and AxisAlignedBoxSceneQuery 
              for full details.
          @par
              The instance returned from this method must be destroyed by calling
              SceneManager::destroyQuery when it is no longer required.
          @param box Details of the box which describes the region for this query.
          @param mask The query mask to apply to this query; can be used to filter out
              certain objects; see SceneQuery for details.
          */
          virtual AxisAlignedBoxSceneQuery* 
              createAABBQuery(const AxisAlignedBox& box, uint32 mask = QUERY_ENTITY_DEFAULT_MASK);
          /** Creates a SphereSceneQuery for this scene manager. 
          @remarks
              This method creates a new instance of a query object for this scene manager, 
              for a spherical region. See SceneQuery and SphereSceneQuery 
              for full details.
          @par
              The instance returned from this method must be destroyed by calling
              SceneManager::destroyQuery when it is no longer required.
          @param sphere Details of the sphere which describes the region for this query.
          @param mask The query mask to apply to this query; can be used to filter out
              certain objects; see SceneQuery for details.
          */
          virtual SphereSceneQuery* 
              createSphereQuery(const Sphere& sphere, uint32 mask = QUERY_ENTITY_DEFAULT_MASK);
          /** Creates a PlaneBoundedVolumeListSceneQuery for this scene manager. 
          @remarks
          This method creates a new instance of a query object for this scene manager, 
          for a region enclosed by a set of planes (normals pointing inwards). 
          See SceneQuery and PlaneBoundedVolumeListSceneQuery for full details.
          @par
          The instance returned from this method must be destroyed by calling
          SceneManager::destroyQuery when it is no longer required.
          @param volumes Details of the volumes which describe the region for this query.
          @param mask The query mask to apply to this query; can be used to filter out
          certain objects; see SceneQuery for details.
          */
          virtual PlaneBoundedVolumeListSceneQuery*  createPlaneBoundedVolumeQuery(
                  const PlaneBoundedVolumeList& volumes, uint32 mask = QUERY_ENTITY_DEFAULT_MASK);
  
  
          /** Creates a RaySceneQuery for this scene manager. 
          @remarks
              This method creates a new instance of a query object for this scene manager, 
              looking for objects which fall along a ray. See SceneQuery and RaySceneQuery 
              for full details.
          @par
              The instance returned from this method must be destroyed by calling
              SceneManager::destroyQuery when it is no longer required.
          @param ray Details of the ray which describes the region for this query.
          @param mask The query mask to apply to this query; can be used to filter out
              certain objects; see SceneQuery for details.
          */
          virtual RaySceneQuery*  createRayQuery(const Ray& ray, uint32 mask = QUERY_ENTITY_DEFAULT_MASK);
          //PyramidSceneQuery* createPyramidQuery(const Pyramid& p, unsigned long mask = 0xFFFFFFFF);
          /** Creates an IntersectionSceneQuery for this scene manager. 
          @remarks
              This method creates a new instance of a query object for locating
              intersecting objects. See SceneQuery and IntersectionSceneQuery
              for full details.
          @par
              The instance returned from this method must be destroyed by calling
              SceneManager::destroyQuery when it is no longer required.
          @param mask The query mask to apply to this query; can be used to filter out
              certain objects; see SceneQuery for details.
          */
          virtual IntersectionSceneQuery* createIntersectionQuery(uint32 mask = QUERY_ENTITY_DEFAULT_MASK);
  
          /** Destroys a scene query of any type. */
          virtual void destroyQuery(SceneQuery* query);
  
          typedef VectorIterator<CameraList> CameraIterator;
          typedef MapIterator<AnimationList> AnimationIterator;
  
          /** Returns a specialised MapIterator over all cameras in the scene. 
          */
          CameraIterator getCameraIterator(void) {
              return CameraIterator(mCameras.begin(), mCameras.end());
          }
          /** Returns a const version of the camera list. 
          */
          const CameraList& getCameras() const { return mCameras; }
          /** Returns a specialised MapIterator over all animations in the scene. */
          AnimationIterator getAnimationIterator(void) {
              return AnimationIterator(mAnimationsList.begin(), mAnimationsList.end());
          }
          /** Returns a const version of the animation list. 
          */
          const AnimationList& getAnimations() const { return mAnimationsList; }
          /** Returns a specialised MapIterator over all animation states in the scene. */
          v1::AnimationStateIterator getAnimationStateIterator(void) {
              return mAnimationStates.getAnimationStateIterator();
          }
  
          /** Set the colour used to modulate areas in shadow. 
          @remarks This is only applicable for shadow techniques which involve 
              darkening the area in shadow, as opposed to masking out the light. 
              This colour provided is used as a modulative value to darken the
              areas.
          */
          virtual void setShadowColour(const ColourValue& colour);
          /** Get the colour used to modulate areas in shadow. 
          @remarks This is only applicable for shadow techniques which involve 
          darkening the area in shadow, as opposed to masking out the light. 
          This colour provided is used as a modulative value to darken the
          areas.
          */
          virtual const ColourValue& getShadowColour(void) const;
          /** Sets the distance a shadow volume is extruded for a directional light.
          @remarks
              Although directional lights are essentially infinite, there are many
              reasons to limit the shadow extrusion distance to a finite number, 
              not least of which is compatibility with older cards (which do not
              support infinite positions), and shadow caster elimination.
          @par
              The default value is 10,000 world units. This does not apply to
              point lights or spotlights, since they extrude up to their 
              attenuation range.
          */
          virtual void setShadowDirectionalLightExtrusionDistance(Real dist); 
          /** Gets the distance a shadow volume is extruded for a directional light.
          */
          virtual Real getShadowDirectionalLightExtrusionDistance(void) const;
          /** Sets the default maximum distance away from the camera that shadows
          will be visible. You have to call this function before you create lights
          or the default distance of zero will be used.
          @remarks
          Shadow techniques can be expensive, therefore it is a good idea
          to limit them to being rendered close to the camera if possible,
          and to skip the expense of rendering shadows for distance objects.
          This method allows you to set the distance at which shadows will no
          longer be rendered.
          @note
          Each shadow technique can interpret this subtely differently.
          For example, one technique may use this to eliminate casters,
          another might use it to attenuate the shadows themselves.
          You should tweak this value to suit your chosen shadow technique
          and scene setup.
          */
          virtual void setShadowFarDistance(Real distance);
          /** Gets the default maximum distance away from the camera that shadows
          will be visible.
          */
          virtual Real getShadowFarDistance(void) const
          { return mDefaultShadowFarDist; }
          virtual Real getShadowFarDistanceSquared(void) const
          { return mDefaultShadowFarDistSquared; }
  
          /** Sets the proportional distance which a texture shadow which is generated from a
              directional light will be offset into the camera view to make best use of texture space.
          @remarks
              When generating a shadow texture from a directional light, an approximation is used
              since it is not possible to render the entire scene to one texture. 
              The texture is projected onto an area centred on the camera, and is
              the shadow far distance * 2 in length (it is square). This wastes
              a lot of texture space outside the frustum though, so this offset allows
              you to move the texture in front of the camera more. However, be aware
              that this can cause a little shadow 'jittering' during rotation, and
              that if you move it too far then you'll start to get artefacts close 
              to the camera. The value is represented as a proportion of the shadow
              far distance, and the default is 0.6.
          */
          virtual void setShadowDirLightTextureOffset(Real offset) { mShadowTextureOffset = offset;}
          /** Gets the proportional distance which a texture shadow which is generated from a
          directional light will be offset into the camera view to make best use of texture space.
          */
          virtual Real getShadowDirLightTextureOffset(void)  const { return mShadowTextureOffset; }
          /** Sets the proportional distance at which texture shadows begin to fade out.
          @remarks
              To hide the edges where texture shadows end (in directional lights)
              Ogre will fade out the shadow in the distance. This value is a proportional
              distance of the entire shadow visibility distance at which the shadow
              begins to fade out. The default is 0.7
          */
          virtual void setShadowTextureFadeStart(Real fadeStart) 
          { mShadowTextureFadeStart = fadeStart; }
          /** Sets the proportional distance at which texture shadows finish to fading out.
          @remarks
          To hide the edges where texture shadows end (in directional lights)
          Ogre will fade out the shadow in the distance. This value is a proportional
          distance of the entire shadow visibility distance at which the shadow
          is completely invisible. The default is 0.9.
          */
          virtual void setShadowTextureFadeEnd(Real fadeEnd) 
          { mShadowTextureFadeEnd = fadeEnd; }
  
          /** Sets the default material to use for rendering shadow casters.
          @remarks
              By default shadow casters are rendered into the shadow texture using
              an automatically generated fixed-function pass. This allows basic
              projective texture shadows, but it's possible to use more advanced
              shadow techniques by overriding the caster materials, for
              example providing vertex and fragment programs to implement shadow
              maps.
          @par
              You can rely on the ambient light in the scene being set to the 
              requested texture shadow colour, if that's useful. 
          @note
              Individual objects may also override the vertex program in
              your default material if their materials include 
              shadow_caster_vertex_program_ref, shadow_caster_material entries,
              so if you use both make sure they are compatible.           
          @note
              Only a single pass is allowed in your material, although multiple
              techniques may be used for hardware fallback.
          */
          virtual void setShadowTextureCasterMaterial(const String& name);
  
          void _setCurrentCompositorPass( CompositorPass *pass );
          /// Note: May be null.
          const CompositorPass* getCurrentCompositorPass(void) const      { return mCurrentPass; }
  
          void _setCurrentShadowNode( CompositorShadowNode *shadowNode, bool isReused );
          const CompositorShadowNode* getCurrentShadowNode(void) const    { return mCurrentShadowNode; }
          bool isCurrentShadowNodeReused(void) const                      { return mShadowNodeIsReused; }
  
          bool isUsingInstancedStereo(void) const;
  
          /** Sets whether to use late material resolving or not. If set, materials will be resolved
              from the materials at the pass-setting stage and not at the render queue building stage.
              This is useful when the active material scheme during the render queue building stage
              is different from the one during the rendering stage.
          */
          virtual void setLateMaterialResolving(bool isLate) { mLateMaterialResolving = isLate; }
          
          /** Gets whether using late material resolving or not.
              @see setLateMaterialResolving */
          virtual bool isLateMaterialResolving() const { return mLateMaterialResolving; }
  
          /** Add a listener which will get called back on scene manager events.
          */
          virtual void addListener(Listener* s);
          /** Remove a listener
          */
          virtual void removeListener(Listener* s);
  
          /** Creates a StaticGeometry instance suitable for use with this
              SceneManager.
          @remarks
              StaticGeometry is a way of batching up geometry into a more 
              efficient form at the expense of being able to move it. Please 
              read the StaticGeometry class documentation for full information.
          @param name The name to give the new object
          @return The new StaticGeometry instance
          */
          virtual v1::StaticGeometry* createStaticGeometry(const String& name);
          /** Retrieve a previously created StaticGeometry instance. 
          @note Throws an exception if the named instance does not exist
          */
          virtual v1::StaticGeometry* getStaticGeometry(const String& name) const;
          /** Returns whether a static geometry instance with the given name exists. */
          virtual bool hasStaticGeometry(const String& name) const;
          /** Remove & destroy a StaticGeometry instance. */
          virtual void destroyStaticGeometry(v1::StaticGeometry* geom);
          /** Remove & destroy a StaticGeometry instance. */
          virtual void destroyStaticGeometry(const String& name);
          /** Remove & destroy all StaticGeometry instances. */
          virtual void destroyAllStaticGeometry(void);
  
          /** Create a movable object of the type specified without a name.
          @remarks
          This is the generalised form of MovableObject creation where you can
          create a MovableObject of any specialised type generically, including
          any new types registered using plugins. The name is generated automatically.
          @param typeName The type of object to create
          @param objectMemMgr Memory Manager that will hold ObjectData data.
          @param params Optional name/value pair list to give extra parameters to
          the created object.
          */
          virtual MovableObject* createMovableObject(const String& typeName,
                                                      ObjectMemoryManager *objectMemMgr,
                                                      const NameValuePairList* params = 0);
          /**
          Returns if this SceneManager contains the specified MovableObject
          */
          virtual bool hasMovableObject( MovableObject *m );
          /** Destroys a MovableObject with the name specified, of the type specified.
          @remarks
              The MovableObject will automatically detach itself from any nodes
              on destruction.
          */
          virtual void destroyMovableObject( MovableObject *m, const String& typeName );
          /** Destroys a MovableObject.
          @remarks
              The MovableObject will automatically detach itself from any nodes
              on destruction.
          */
          virtual void destroyMovableObject(MovableObject* m);
          /** Destroy all MovableObjects of a given type. */
          virtual void destroyAllMovableObjectsByType(const String& typeName);
          /** Destroy all MovableObjects. */
          virtual void destroyAllMovableObjects(void);
          typedef VectorIterator<MovableObjectVec> MovableObjectIterator;
          /** Get an iterator over all MovableObect instances of a given type. 
          @note
              The iterator returned from this method is not thread safe, do not use this
              if you are creating or deleting objects of this type in another thread.
          */
          virtual MovableObjectIterator getMovableObjectIterator(const String& typeName);
          /** Inject a MovableObject instance created externally.
          @remarks
              This method 'injects' a MovableObject instance created externally into
              the MovableObject instance registry held in the SceneManager. You
              might want to use this if you have a MovableObject which you don't
              want to register a factory for; for example a MovableObject which 
              cannot be generally constructed by clients. 
          @note
              It is important that the MovableObject has a unique name for the type,
              and that its getMovableType() method returns a proper type name.
          */
          virtual void injectMovableObject(MovableObject* m);
          /** Extract a previously injected MovableObject.
          @remarks
              Essentially this does the same as destroyMovableObject, but only
              removes the instance from the internal lists, it does not attempt
              to destroy it.
          */
          virtual void extractMovableObject(MovableObject* m);
          /** Extract all injected MovableObjects of a given type.
          @remarks
              Essentially this does the same as destroyAllMovableObjectsByType, 
              but only removes the instances from the internal lists, it does not 
              attempt to destroy them.
          */
          virtual void extractAllMovableObjectsByType(const String& typeName);
  
          /** Sets a mask which is bitwise 'and'ed with objects own visibility masks
              to determine if the object is visible.
          @remarks
              Note that this is combined with any per-viewport visibility mask
              through an 'and' operation. @see Viewport::setVisibilityMask
          */
          virtual_l2 void setVisibilityMask(uint32 vmask)
                                  { mVisibilityMask = vmask & VisibilityFlags::RESERVED_VISIBILITY_FLAGS; }
  
          /** Gets a mask which is bitwise 'and'ed with objects own visibility masks
              to determine if the object is visible.
          */
          virtual_l2 uint32 getVisibilityMask(void) const { return mVisibilityMask; }
  
          /** Internal method for getting the combination between the global visibility
              mask and the per-viewport visibility mask.
          */
          uint32 _getCombinedVisibilityMask(void) const;
  
          /** Sets a mask which is bitwise 'and'ed with lights' own light masks
              to determine if the light should be casting light.
          @remarks
              Note that this is combined with any per-pass light mask
              through an 'and' operation.
  
              @see    CompositorPassSceneDef::mLightVisibilityMask
              @see    Viewport::getLightVisibilityMask
          */
          virtual_l2 void setLightMask(uint32 mask)   { mLightMask = mask; }
  
          /** Gets a mask which is bitwise 'and'ed with lights' own light masks
              to determine if the light should be casting light.
          */
          virtual_l2 uint32 getLightMask(void) const  { return mLightMask; }
  
          /** Sets whether the SceneManager should search for visible objects, or
              whether they are being manually handled.
          @remarks
              This is an advanced function, you should not use this unless you know
              what you are doing.
          */
          virtual void setFindVisibleObjects(bool find) { mFindVisibleObjects = find; }
  
          /** Gets whether the SceneManager should search for visible objects, or
              whether they are being manually handled.
          */
          virtual bool getFindVisibleObjects(void) { return mFindVisibleObjects; }
  
          /** Set whether to automatically flip the culling mode on objects whenever they
              are negatively scaled.
          @remarks
              Negativelyl scaling an object has the effect of flipping the triangles, 
              so the culling mode should probably be inverted to deal with this. 
              If you would prefer to manually manage this, set this option to 'false' 
              and use different materials with Pass::setCullingMode set manually as needed.
          */
          virtual void setFlipCullingOnNegativeScale(bool n) { mFlipCullingOnNegativeScale = n; }
  
          /** Get whether to automatically flip the culling mode on objects whenever they
              are negatively scaled.
          */
          virtual bool getFlipCullingOnNegativeScale() const { return mFlipCullingOnNegativeScale; }
  
          virtual void _renderSingleObject( Renderable* pRend, const MovableObject *pMovableObject,
                                            bool casterPass, bool dualParaboloid );
  
          /** Indicates to the SceneManager whether it should suppress changing
              the RenderSystem states when rendering objects.
          @remarks
              This method allows you to tell the SceneManager not to change any
              RenderSystem state until you tell it to. This method is only 
              intended for advanced use, don't use it if you're unsure of the 
              effect. The only RenderSystems calls made are to set the world 
              matrix for each object (note - view an projection matrices are NOT
              SET - they are under your control) and to render the object; it is up to 
              the caller to do everything else, including enabling any vertex / 
              fragment programs and updating their parameter state, and binding
              parameters to the RenderSystem.
          @note
              Calling this implicitly disables shadow processing since no shadows
              can be rendered without changing state.
          @param suppress If true, no RenderSystem state changes will be issued
              until this method is called again with a parameter of false.
          */
          virtual void _suppressRenderStateChanges(bool suppress);
          
          /** Are render state changes suppressed? 
          @see _suppressRenderStateChanges
          */
          virtual bool _areRenderStateChangesSuppressed(void) const
          { return mSuppressRenderStateChanges; }
          
          /** Method to allow you to mark gpu parameters as dirty, causing them to 
              be updated according to the mask that you set when updateGpuProgramParameters is
              next called. Only really useful if you're controlling parameter state in 
              inner rendering loop callbacks.
              @param mask Some combination of GpuParamVariability which is bitwise OR'ed with the
                  current dirty state.
          */
          virtual void _markGpuParamsDirty(uint16 mask);
  
          /** Get the rendersystem subclass to which the output of this Scene Manager
              gets sent
          */
          RenderSystem *getDestinationRenderSystem();
  
          /** Gets the current viewport being rendered (advanced use only, only 
              valid during viewport update. */
          Viewport* getCurrentViewport0(void) const { return mCurrentViewport0; }
  
          /** Gets the current camera being rendered (advanced use only, only 
              valid during viewport update. */
          CamerasInProgress getCamerasInProgress(void) const     { return mCamerasInProgress; }
  
          AxisAlignedBox _calculateCurrentCastersBox( uint32 viewportVisibilityMask,
                                                      uint8 firstRq, uint8 lastRq ) const;
  
          /** @See CompositorShadowNode::getCastersBox
          @remarks
              Returns a null box if no active shadow node.
          */
          const AxisAlignedBox& getCurrentCastersBox(void) const;
  
          /** @See CompositorShadowNode::getMinMaxDepthRange
          @remarks
              Outputs 0 & 100000 if no active shadow node or camera not found.
          */
          void getMinMaxDepthRange( const Frustum *shadowMapCamera, Real &outMin, Real &outMax ) const;
  
  
          /** Set whether to use relative offset co-ordinates when rendering, ie
              offset to subtract to the camera, lights & objects.
          @remarks
              This is a technique to alleviate some of the precision issues associated with 
              rendering far from the origin, where single-precision floats as used in most
              GPUs begin to lose their precision. The origin "translates" to this new
              relativeOffset.
              Any previous non-permanent origin is overriden
          @par
              All that this function performs is just offseting the root scene node, and
              as such, will force to update the static nodes as well. Call this at a low
              frequency (i.e. when camera has gone too far from origin)
          @note
              If you need this option, you will probably also need to enable double-precision
              mode in Ogre (OGRE_DOUBLE_PRECISION), since even though this will 
              alleviate the rendering precision, the source camera and object positions will still 
              suffer from precision issues leading to jerky movement. 
          @param bPermanent
              When false, it only affects the root nodes (static & dynamic) so that everything is
              shifted by the relative origin, causing world & view matrices to contain smaller
              values. This improves the quality of skeletal animations and "Z fighting"-like
              artifacts because vertices don't snap to the right place.
              However, it won't fix the jittering of objects observed while translating them by
              small increments, including camera movement.
  
              Setting this value to true will force the SceneManager to propagate the change
              as much as possible to child nodes (including attached Cameras), causing
              the change to become permanent/irreversible. This achieves greater quality
              since translating objects or camera by small amounts now gets more accuracy.
              @See propagateRelativeOrigin.
          */
          virtual void setRelativeOrigin( const Vector3 &relativeOrigin, bool bPermanent );
  
          /// Returns the current relative origin. (Only when non-permanent)
          Vector3 getRelativeOrigin(void) const;
  
          /** Add a level of detail listener. */
          void addLodListener(LodListener *listener);
  
          /**
          Remove a level of detail listener.
          @remarks
              Do not call from inside an LodListener callback method.
          */
          void removeLodListener(LodListener *listener);
  
          /** Notify that a movable object LOD change event has occurred. */
          void _notifyMovableObjectLodChanged(MovableObjectLodChangedEvent& evt);
  
          /** Notify that an entity mesh LOD change event has occurred. */
          void _notifyEntityMeshLodChanged(EntityMeshLodChangedEvent& evt);
  
          /** Notify that an entity material LOD change event has occurred. */
          void _notifyEntityMaterialLodChanged(EntityMaterialLodChangedEvent& evt);
  
          /** Handle LOD events. */
          void _handleLodEvents();
  
          void _setCurrentRenderStage( IlluminationRenderStage stage ) { mIlluminationStage = stage; }
          IlluminationRenderStage _getCurrentRenderStage() const {return mIlluminationStage;}
  
      protected:
  
          void fireWorkerThreadsAndWait(void);
  
          /** Launches cullFrustum on all worker threads with the requested parameters
          @remarks
              Will block until all threads are done.
          */
          void fireCullFrustumThreads( const CullFrustumRequest &request );
          void startWorkerThreads();
          void stopWorkerThreads();
  
      public:
  
          /** Processes a user-defined UniformScalableTask in the worker threads
              spawned by SceneManager.
          @remarks
              If 'bBlock' is false, it is user responsibility to call
              waitForPendingUserScalableTask before the next call to either
              processUserScalableTask or renderOneFrame.
          @param task
              Task to perform. Pointer must be valid at least until the task is finished
          @param bBlock
              True if you want the function to block until the task is done.
              False if you want to do something in between, in this case you MUST
              call waitForPendingUserScalableTask later.
          */
          void executeUserScalableTask( UniformScalableTask *task, bool bBlock );
  
          /** Blocks until the the task from processUserScalableTask finishes.
          @remarks
              Do NOT call this function if you passed bBlock = true to processUserScalableTask
          */
          void waitForPendingUserScalableTask();
  
          /** Called from the worker thread, polls to process frustum culling
              requests when a sync is performed
          */
          unsigned long _updateWorkerThread( ThreadHandle *threadHandle );
      protected:
          inline bool updateWorkerThreadImpl( size_t threadIdx );
      };
  
      /** Default implementation of IntersectionSceneQuery. */
      class _OgreExport DefaultIntersectionSceneQuery : 
          public IntersectionSceneQuery
      {
      public:
          DefaultIntersectionSceneQuery(SceneManager* creator);
          ~DefaultIntersectionSceneQuery();
  
          /** See IntersectionSceneQuery. */
          void execute(IntersectionSceneQueryListener* listener);
      };
  
      /** Default implementation of RaySceneQuery. */
      class _OgreExport DefaultRaySceneQuery : public RaySceneQuery
      {
      public:
          DefaultRaySceneQuery(SceneManager* creator);
          ~DefaultRaySceneQuery();
  
          /** See RayScenQuery. */
          virtual void execute(RaySceneQueryListener* listener);
          bool execute( ObjectData objData, size_t numNodes, RaySceneQueryListener* listener );
  
      private:
          using RaySceneQuery::execute;  // Shut up compiler warnings
      };
      /** Default implementation of SphereSceneQuery. */
      class _OgreExport DefaultSphereSceneQuery : public SphereSceneQuery
      {
      public:
          DefaultSphereSceneQuery(SceneManager* creator);
          ~DefaultSphereSceneQuery();
  
          /** See SceneQuery. */
          virtual void execute(SceneQueryListener* listener);
          bool execute( ObjectData objData, size_t numNodes, SceneQueryListener* listener );
  
      private:
          using SphereSceneQuery::execute;  // Shut up compiler warnings
      };
      /** Default implementation of PlaneBoundedVolumeListSceneQuery. */
      class _OgreExport DefaultPlaneBoundedVolumeListSceneQuery : public PlaneBoundedVolumeListSceneQuery
      {
      public:
          DefaultPlaneBoundedVolumeListSceneQuery(SceneManager* creator);
          ~DefaultPlaneBoundedVolumeListSceneQuery();
  
          /** See SceneQuery. */
          void execute(SceneQueryListener* listener);
          bool execute(ObjectData objData, size_t numNodes, SceneQueryListener* listener);
  
      private:
          using PlaneBoundedVolumeListSceneQuery::execute;  // Shut up compiler warnings
  
          //SIMD friendly version of a plane
          struct ArrayPlane
          {
              ArrayVector3    planeNormal;
              ArrayVector3    signFlip;
              ArrayReal       planeNegD;
          };
  
          //List to store SIMD friendly planes and ensure that the memory is properly aligned
          RawSimdUniquePtr<ArrayPlane, MEMCATEGORY_GENERAL> mSimdPlaneList;
      };
      /** Default implementation of AxisAlignedBoxSceneQuery. */
      class _OgreExport DefaultAxisAlignedBoxSceneQuery : public AxisAlignedBoxSceneQuery
      {
      public:
          DefaultAxisAlignedBoxSceneQuery(SceneManager* creator);
          ~DefaultAxisAlignedBoxSceneQuery();
  
          /** See RayScenQuery. */
          virtual void execute(SceneQueryListener* listener);
          bool execute( ObjectData objData, size_t numNodes, SceneQueryListener* listener );
  
      private:
          using AxisAlignedBoxSceneQuery::execute;  // Shut up compiler warnings
      };
      
  
      /// Bitmask containing scene types
      typedef uint16 SceneTypeMask;
  
      /** Classification of a scene to allow a decision of what type of
      SceenManager to provide back to the application.
      */
      enum SceneType
      {
          ST_GENERIC = 1,
          ST_EXTERIOR_CLOSE = 2,
          ST_EXTERIOR_FAR = 4,
          ST_EXTERIOR_REAL_FAR = 8,
          ST_INTERIOR = 16
      };
  
      /** Structure containing information about a scene manager. */
      struct SceneManagerMetaData
      {
          /// A globally unique string identifying the scene manager type
          String typeName;
          /// A text description of the scene manager
          String description;
          /// A mask describing which sorts of scenes this manager can handle
          SceneTypeMask sceneTypeMask;
          /// Flag indicating whether world geometry is supported
          bool worldGeometrySupported;
      };
  
  
  
      /** Class which will create instances of a given SceneManager. */
      class _OgreExport SceneManagerFactory : public SceneMgtAlloc
      {
      protected:
          mutable SceneManagerMetaData mMetaData;
          mutable bool mMetaDataInit;
          /// Internal method to initialise the metadata, must be implemented
          virtual void initMetaData(void) const = 0;
      public:
          SceneManagerFactory() : mMetaDataInit(true) {}
          virtual ~SceneManagerFactory();
          /** Get information about the SceneManager type created by this factory. */
          virtual const SceneManagerMetaData& getMetaData(void) const 
          {
              if (mMetaDataInit)
              {
                  initMetaData();
                  mMetaDataInit = false;
              }
              return mMetaData; 
          }
          /** Create a new instance of a SceneManager.
          @remarks
          Don't call directly, use SceneManagerEnumerator::createSceneManager.
          */
          virtual SceneManager* createInstance(const String& instanceName, size_t numWorkerThreads) = 0;
          /** Destroy an instance of a SceneManager. */
          virtual void destroyInstance(SceneManager* instance) = 0;
  
      };
  
      /** @} */
      /** @} */
  
  
  } // Namespace
  
  #include "OgreHeaderSuffix.h"
  
  #endif
  