static void CreateDebriPiece (const NewtonBody* sourceBody, NewtonMesh* mesh, dFloat volume)
{
	dFloat Ixx;
	dFloat Iyy;
	dFloat Izz;
	dFloat mass;
	dFloat shapeVolume;
	NewtonWorld* world;
	NewtonBody* rigidBody;
	NewtonCollision* collision;
	OGLMesh* meshInstance;
	SceneManager* system;
	RenderPrimitive* primitive;
	dVector inertia;
	dVector origin;
	dVector veloc;
	dVector omega;
	dMatrix matrix;

	world = NewtonBodyGetWorld (sourceBody);

	NewtonBodyGetMatrix (sourceBody, &matrix[0][0]);

	NewtonBodyGetMassMatrix (sourceBody, &mass, &Ixx, &Iyy, &Izz);

	// make a visual object
	meshInstance = new OGLMesh();

	meshInstance->BuildFromMesh (mesh);

	// create a visual geometry
	primitive = new RenderPrimitive (matrix, meshInstance);
	meshInstance->Release();

	// save the graphics system
	system = (SceneManager*) NewtonWorldGetUserData(world);
	system->AddModel (primitive);

	collision = NewtonCreateConvexHullFromMesh (world, mesh, 0.1f, DEBRI_ID);

	// calculate the moment of inertia and the relative center of mass of the solid
	shapeVolume = NewtonConvexCollisionCalculateVolume (collision);
	NewtonConvexCollisionCalculateInertialMatrix (collision, &inertia[0], &origin[0]);	

	mass = mass * shapeVolume / volume;
	Ixx = mass * inertia[0];
	Iyy = mass * inertia[1];
	Izz = mass * inertia[2];

	//create the rigid body
	rigidBody = NewtonCreateBody (world, collision);

	// set the correct center of gravity for this body
	NewtonBodySetCentreOfMass (rigidBody, &origin[0]);

	// set the mass matrix
	NewtonBodySetMassMatrix (rigidBody, mass, Ixx, Iyy, Izz);

	// save the pointer to the graphic object with the body.
	NewtonBodySetUserData (rigidBody, primitive);

	// assign the wood id
//	NewtonBodySetMaterialGroupID (rigidBody, NewtonBodyGetMaterialGroupID(source));

	// set continue collision mode
	NewtonBodySetContinuousCollisionMode (rigidBody, 1);

	// set a destructor for this rigid body
	NewtonBodySetDestructorCallback (rigidBody, PhysicsBodyDestructor);

	// set the transform call back function
	NewtonBodySetTransformCallback (rigidBody, PhysicsSetTransform);

	// set the force and torque call back function
	NewtonBodySetForceAndTorqueCallback (rigidBody, PhysicsApplyGravityForce);

	// set the matrix for both the rigid body and the graphic body
	NewtonBodySetMatrix (rigidBody, &matrix[0][0]);
	PhysicsSetTransform (rigidBody, &matrix[0][0], 0);

	NewtonBodyGetVelocity(sourceBody, &veloc[0]);
	NewtonBodyGetOmega(sourceBody, &omega[0]);
	veloc += omega * matrix.RotateVector(origin);

// for now so that I can see the body
veloc = dVector (0, 0, 0, 0);
//	omega = dVector (0, 0, 0, 0);

	NewtonBodySetVelocity(rigidBody, &veloc[0]);
	NewtonBodySetOmega(rigidBody, &omega[0]);

	NewtonReleaseCollision(world, collision);

}
static void BuildFloorAndSceneRoot (SceneManager& system)
{
	NewtonWorld* world;
	RenderPrimitive* floor;
	NewtonBody* floorBody;
	NewtonCollision* floorCollision;
	OGLMesh* meshInstance;

	world = system.m_world;
	// /////////////////////////////////////////////////////////////////////
	//
	// create the sky box,
	system.AddModel (new SkyBox ());


	// create the the floor graphic objects
	dVector floorSize (100.0f, 2.0f, 100.0f);
	dMatrix location (GetIdentityMatrix());
	location.m_posit.m_y = -5.0f; 

	// create a box for floor 
	floorCollision = NewtonCreateBox (world, floorSize.m_x, floorSize.m_y, floorSize.m_z, 0, NULL); 

	//	meshInstance = OGLMesh::MakeBox (world, size.m_x, size.m_y, size.m_z, "GrassAndDirt.tga");
	meshInstance = new OGLMesh (floorCollision, "GrassAndDirt.tga", "metal_30.tga", "metal_30.tga");
	floor = new RenderPrimitive (location, meshInstance);
	system.AddModel (floor);
	meshInstance->Release();

	// create the the floor collision, and body with default values
	floorBody = NewtonCreateBody (world, floorCollision);
	NewtonReleaseCollision (world, floorCollision);


	// set the transformation for this rigid body
	NewtonBodySetMatrix (floorBody, &location[0][0]);

	// save the pointer to the graphic object with the body.
	NewtonBodySetUserData (floorBody, floor);

	// set a destructor for this rigid body
	NewtonBodySetDestructorCallback (floorBody, PhysicsBodyDestructor);


	// get the default material ID
	int defaultID;
	defaultID = NewtonMaterialGetDefaultGroupID (world);

	// set default material properties
	NewtonMaterialSetDefaultSoftness (world, defaultID, defaultID, 0.05f);
	NewtonMaterialSetDefaultElasticity (world, defaultID, defaultID, 0.4f);
	NewtonMaterialSetDefaultCollidable (world, defaultID, defaultID, 1);
	NewtonMaterialSetDefaultFriction (world, defaultID, defaultID, 1.0f, 0.5f);
	NewtonMaterialSetCollisionCallback (world, defaultID, defaultID, NULL, NULL, GenericContactProcess); 

	//	NewtonMaterialSetSurfaceThickness(world, materialID, materialID, 0.1f);
	NewtonMaterialSetSurfaceThickness(world, defaultID, defaultID, 0.0f);

	// set the island update callback
	NewtonSetIslandUpdateEvent (world, PhysicsIslandUpdate);

	// save the callback
	SetDemoCallbacks (system);

	InitEyePoint (dVector (1.0f, 0.0f, 0.0f), dVector (-40.0f, 10.0f, 0.0f));
}