+ /** Returns a bounding sphere that completely encloses the Renderable. The
+ bounding sphere is expressed in the renderable's coordinates. Null is
+ returned if the bounding sphere cannot be determined. */
+ virtual const Geometry::BoundingSphere<float, 3> *get_bounding_sphere() const { return 0; }
+
+ /** Called when starting to render a new frame. */
+ virtual void setup_frame() const { }
+
+ /** Called when a complete frame has been rendered. */
+ virtual void finish_frame() const { }
+
+ /** Renders the Renderable without a renderer. This can be convenient in