text: //////////////////////////////////////////////////////////////////////////
  //
  //  Copyright (c) 2009-2011, Image Engine Design Inc. All rights reserved.
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  //////////////////////////////////////////////////////////////////////////
  
  #ifndef IECORE_SIMPLESUBSURFACE_H
  #define IECORE_SIMPLESUBSURFACE_H
  
  #include "IECore/RefCounted.h"
  #include "IECore/KDTree.h"
  #include "IECore/VectorTypedData.h"
  #include "IECore/Spline.h"
  
  namespace IECore
  {
  
  /// A simple subsurface scattering implementation using a hierarchical pointcloud. Rather
  /// than use the standard dipole approximation it allows the falloff to be controlled
  /// explicitly using a spline.
  /// \ingroup renderingGroup
  class SimpleSubsurface : public IECore::RefCounted
  {
  
  	public :
  	
  		IE_CORE_DECLAREMEMBERPTR( SimpleSubsurface );
  	
  		SimpleSubsurface( ConstV3fVectorDataPtr p, ConstColor3fVectorDataPtr c, ConstFloatVectorDataPtr a, const SplinefColor3f &falloff );
  		virtual ~SimpleSubsurface();
  		
  		Imath::Color3f lookup( const Imath::V3f &p, float radius ) const;
  		
  	private :
  
  		typedef V3fTree Tree;
  
  		struct PrivateData;
  		boost::shared_ptr<PrivateData> m_privateData;
  		
  		void buildWalk( Tree::NodeIndex nodeIndex );
  
  		inline void accum( const Imath::V3f &p, float radius, const Imath::V3f &sampleP, const Imath::Color3f &sampleC, Imath::Color3f &result ) const;
  		void lookupWalk( Tree::NodeIndex nodeIndex, const Imath::V3f &p, float radius, Imath::Color3f &result ) const;
  		
  };
  
  IE_CORE_DECLAREPTR( SimpleSubsurface );
  
  } // namespace IECore
  
  #endif // IECORE_SIMPLESUBSURFACE_H
  