/// <summary>
        /// This sets the position to use for the thing geometry.
        /// </summary>
        public void SetPosition(Vector3D pos)
        {
            position_v3 = D3DDevice.V3(pos);             //mxd
            position    = Matrix.Translation(position_v3);
            updategeo   = true;
            updatecage  = true;            //mxd

            //mxd. update bounding box?
            if (lightType != null && lightRadius > thing.Size)
            {
                UpdateBoundingBox(lightRadius, lightRadius * 2);
            }
        }
 /// <summary>
 /// This sets the position to use for the thing geometry.
 /// </summary>
 public void SetPosition(Vector3D pos)
 {
     pos2d    = new Vector2D(pos);
     position = Matrix.Translation(D3DDevice.V3(pos));
 }