public abstract void SetAngularVelocity(BulletBody obj, Vector3 angularVelocity);
 public abstract void UpdateDeactivation(BulletBody obj, float timeStep);
 // =====================================================================================
 // btCollisionWorld entries
 public abstract void UpdateSingleAabb(BulletWorld world, BulletBody obj);
 public abstract void SetSleepingThresholds(BulletBody obj, float lin_threshold, float ang_threshold);
 public abstract void SetUserPointer(BulletBody obj, IntPtr val);
 public abstract void SetLinearVelocity(BulletBody obj, Vector3 val);
 // Set the force being applied to the object as if its mass is one.
 public abstract void SetObjectForce(BulletBody obj, Vector3 force);
 public abstract void SetCollisionShape(BulletWorld sim, BulletBody obj, BulletShape shape);
 public abstract void SetContactProcessingThreshold(BulletBody obj, float val);
 public abstract CollisionFlags SetCollisionFlags(BulletBody obj, CollisionFlags flags);
 public abstract bool SetCollisionGroupMask(BulletBody body, UInt32 filter, UInt32 mask);
 public abstract void SetCenterOfMassByPosRot(BulletBody obj, Vector3 pos, Quaternion rot);
 public abstract void SetCcdSweptSphereRadius(BulletBody obj, float val);
 public abstract void SetCcdMotionThreshold(BulletBody obj, float val);
 public abstract void SetLinearDamping(BulletBody obj, float lin_damping);
 public abstract void SetDamping(BulletBody obj, float lin_damping, float ang_damping);
 public abstract void SetLinearFactor(BulletBody obj, Vector3 factor);
 public abstract void SetDeactivationTime(BulletBody obj, float dtime);
 public abstract void SetMassProps(BulletBody obj, float mass, Vector3 inertia);
 public abstract void SetGravity(BulletBody obj, Vector3 val);
 public abstract void SetRestitution(BulletBody obj, float val);
 public abstract void SetHitFraction(BulletBody obj, float val);
 public abstract void SetTranslation(BulletBody obj, Vector3 position, Quaternion rotation);
 // public abstract IntPtr GetBroadphaseHandle(BulletBody obj);
 // public abstract void SetBroadphaseHandle(BulletBody obj, IntPtr handle);
 public abstract void SetInterpolationLinearVelocity(BulletBody obj, Vector3 vel);
 public abstract void Translate(BulletBody obj, Vector3 trans);
 public abstract void SetInterpolationVelocity(BulletBody obj, Vector3 linearVel, Vector3 angularVel);
 public abstract void UpdateInertiaTensor(BulletBody obj);
 public abstract void SetInvInertiaDiagLocal(BulletBody obj, Vector3 inert);
 public abstract bool WantsSleeping(BulletBody obj);
 public abstract void SetAngularFactorV(BulletBody obj, Vector3 factor);