private UWB_Primitive CreateSphereMesh()
 {
     UWB_XNAPrimitiveMesh m = new UWB_XNAPrimitiveMesh("sphere");
     m.EnableTexturing(false);
     m.EnableLighting(true);
     return m;
 }
 private UWB_Primitive CreateRectangle(RTRectangle r)
 {
     UWB_XNAPrimitiveMesh m = new UWB_XNAPrimitiveMesh("HiResFloor");
     m.EnableTexturing(false);
     m.EnableLighting(true);
     return m;
 }