anchor.diff:  
   == Add PhysicsControl to PhysicsSpace
   
  -The PhysicsSpace is an object in BulletAppState that is like a rootNode for Physics Controls. 
  -
  -*  Just like you add the Geometry to the rootNode, you add its PhysicsControl to the PhysicsSpace. 
  -[source,java]
  -----
  -bulletAppState.getPhysicsSpace().add(myThing_phys); 
  -rootNode.attachChild(myThing_geo); 
  -----
  -
  -*  When you remove a Geometry from the scene and detach it from the rootNode, also remove the PhysicsControl from the PhysicsSpace: 
  +The PhysicsSpace is an object in BulletAppState that is like a rootNode for Physics Controls.
  +
  +*  Just like you add the Geometry to the rootNode, you add its PhysicsControl to the PhysicsSpace.
  +[source,java]
  +----
  +bulletAppState.getPhysicsSpace().add(myThing_phys);
  +rootNode.attachChild(myThing_geo);
  +----
  +
  +*  When you remove a Geometry from the scene and detach it from the rootNode, also remove the PhysicsControl from the PhysicsSpace:
   [source,java]
   ----
   bulletAppState.getPhysicsSpace().remove(myThing_phys);
  
positive.code: 
  === Physics Control Code Samples
  
  The most commonly used physics control is RigidBodyControl.  The RigidBodyControl constructor takes up to two parameters:  a collision shape and a mass (a float in kilograms).  The mass parameter also determines whether the object is dynamic (movable) or static (fixed). For a static object such as a floor or wall, specify zero mass. 
  
  [source,java]
  ----
  RigidBodyControl myThing_phys = 
      new RigidBodyControl( myThing_shape , 123.0f ); // dynamic
  ----
  
  [source,java]
  ----
  RigidBodyControl myDungeon_phys = 
      new RigidBodyControl( myDungeon_shape , 0.0f ); // static 
  ----
  
  
  
negative.code: a|Set the amount of rotation that will be applied. A value of zero will cancel all rotational force outcome. (?)
  
  a| setSleepingThreshold(float,float)
  a|Sets the sleeping thresholds which define when the object gets deactivated to save resources. The first value is the linear threshold and the second the angular. Low values keep the object active when it barely moves (slow precise performance), high values put the object to sleep immediately (imprecise fast performance). (?)
  
  a| setCcdMotionThreshold(0f)
  a|Sets the amount of motion that has to happen in one physics tick to trigger the continuous motion detection in moving objects that push one another. This avoids the problem of fast objects moving through other objects. Set to zero to disable (default).
  
  a| setCcdSweptSphereRadius(.5f)
  a|Bullet does not use the full collision shape for continuous collision detection, instead it uses a “swept sphere shape to approximate a motion, which can be imprecise and cause strange behaviors such as objects passing through one another or getting stuck. Only relevant for fast moving dynamic bodies.
  
  |===
  
  