public BSConstraint6Dof(BulletWorld world, BulletBody obj1, BulletBody obj2)
     : base(world)
 {
     m_body1 = obj1;
     m_body2 = obj2;
     m_enabled = false;
 }

 public BSConstraintConeTwist(BulletWorld world, BulletBody obj1, BulletBody obj2,
                 Vector3 frameInAloc, Quaternion frameInArot,
                 Vector3 frameInBloc, Quaternion frameInBrot,
                 bool disableCollisionsBetweenLinkedBodies)
     : base(world)
 {
     m_body1 = obj1;
     m_body2 = obj2;
     m_constraint = PhysicsScene.PE.CreateConeTwistConstraint(world, obj1, obj2,
                             frameInAloc, frameInArot, frameInBloc, frameInBrot,
                             disableCollisionsBetweenLinkedBodies);
     m_enabled = true;
 }

 public BSConstraintSlider(BulletWorld world, BulletBody obj1, BulletBody obj2,
             Vector3 frameInAloc, Quaternion frameInArot,
             Vector3 frameInBloc, Quaternion frameInBrot,
             bool useLinearReferenceFrameA, bool disableCollisionsBetweenLinkedBodies)
     : base(world)
 {
     m_body1 = obj1;
     m_body2 = obj2;
     m_constraint = PhysicsScene.PE.CreateSliderConstraint(world, obj1, obj2,
                         frameInAloc, frameInArot, frameInBloc, frameInBrot,
                         useLinearReferenceFrameA, disableCollisionsBetweenLinkedBodies);
     m_enabled = true;
 }

 public BSConstraintHinge(BulletWorld world, BulletBody obj1, BulletBody obj2,
     Vector3 pivotInA, Vector3 pivotInB,
     Vector3 axisInA, Vector3 axisInB,
     bool useLinearReferenceFrameA, bool disableCollisionsBetweenLinkedBodies)
     : base(world)
 {
     m_body1 = obj1;
     m_body2 = obj2;
     m_constraint = PhysicsScene.PE.CreateHingeConstraint(world, obj1, obj2,
         pivotInA, pivotInB, axisInA, axisInB,
         useLinearReferenceFrameA, disableCollisionsBetweenLinkedBodies);
     m_enabled = true;
 }

        public BSConstraintSpring(BulletWorld world, BulletBody obj1, BulletBody obj2,
                        Vector3 frame1Loc, Quaternion frame1Rot,
                        Vector3 frame2Loc, Quaternion frame2Rot,
                        bool useLinearReferenceFrameA, bool disableCollisionsBetweenLinkedBodies)
            : base(world, obj1, obj2)
        {
            m_constraint = PhysicsScene.PE.Create6DofSpringConstraint(world, obj1, obj2,
                                    frame1Loc, frame1Rot, frame2Loc, frame2Rot,
                                    useLinearReferenceFrameA, disableCollisionsBetweenLinkedBodies);
            m_enabled = true;

            PhysicsScene.DetailLog("{0},BSConstraintSpring,create,wID={1}, rID={2}, rBody={3}, cID={4}, cBody={5}",
                                obj1.ID, world.worldID, obj1.ID, obj1.AddrString, obj2.ID, obj2.AddrString);
            PhysicsScene.DetailLog("{0},BSConstraintSpring,create,  f1Loc={1},f1Rot={2},f2Loc={3},f2Rot={4},usefA={5},disCol={6}",
                        m_body1.ID, frame1Loc, frame1Rot, frame2Loc, frame2Rot, useLinearReferenceFrameA, disableCollisionsBetweenLinkedBodies);
        }

 // Create a btGeneric6DofConstraint
 public BSConstraint6Dof(BulletWorld world, BulletBody obj1, BulletBody obj2,
     Vector3 frame1, Quaternion frame1rot,
     Vector3 frame2, Quaternion frame2rot,
     bool useLinearReferenceFrameA, bool disableCollisionsBetweenLinkedBodies)
     : base(world)
 {
     m_body1 = obj1;
     m_body2 = obj2;
     m_constraint = PhysicsScene.PE.Create6DofConstraint(m_world, m_body1, m_body2,
         frame1, frame1rot,
         frame2, frame2rot,
         useLinearReferenceFrameA, disableCollisionsBetweenLinkedBodies);
     m_enabled = true;
     world.physicsScene.DetailLog(
         "{0},BS6DofConstraint,createFrame,wID={1}, rID={2}, rBody={3}, cID={4}, cBody={5}",
         BSScene.DetailLogZero, world.worldID,
         obj1.ID, obj1.AddrString, obj2.ID, obj2.AddrString);
 }

 // =====================================================================================
 // btCollisionWorld entries
 public abstract void UpdateSingleAabb(BulletWorld world, BulletBody obj);

 public abstract void UpdateAabbs(BulletWorld world);

 public abstract void SetForceUpdateAllAabbs(BulletWorld world, bool force);

 public virtual void ResetConstraintSolver(BulletWorld sim)
 {
 }

 public abstract bool RemoveObjectFromWorld(BulletWorld world, BulletBody obj);

 public abstract int PhysicsStep(BulletWorld world, float timeStep, int maxSubSteps, float fixedTimeStep,
     out int updatedEntityCount, out int collidersCount);

 public abstract void DestroyObject(BulletWorld sim, BulletBody obj);

 public abstract bool DestroyConstraint(BulletWorld world, BulletConstraint constrain);

 public abstract bool GetForceUpdateAllAabbs(BulletWorld world);

 public abstract bool IsInWorld(BulletWorld world, BulletBody obj);

 public virtual void DumpActivationInfo(BulletWorld sim)
 {
 }

 public abstract bool RemoveConstraintFromWorld(BulletWorld world, BulletConstraint constrain);

 public virtual void DumpAllInfo(BulletWorld sim)
 {
 }

 public virtual void ResetBroadphasePool(BulletWorld sim)
 {
 }