Some Drawable may also be {@link plot3d.rendering.Wireframeable3d} to offer wireframe display control on 3d objects for which it make sense: Polygons, Spheres, etc. A Point has obviously no existing wireframe mode.
Pure Drawable are implicitely considered as Primitive shapes and provide a function for drawing themself. A Composite3d may encapsulate several Primitives and delegate rendering or transformation to its Primitives.
When designing a Composite3d, the programer must be aware that no real SceneGraph is currently available, and that the glscale, glrotate and gltransform calls must be set statically into the draw function of the Composite3d.