I have done a large commit to CVS which includes, along with lots of  
stuff which no doubt is buggy and will break things :-) a significant  
rewrite of SpherePortrayal3D, ShapePortrayal3D, CylinderPortrayal3D,  
and ConePortrayal3D, and some additions to SimplePortrayal3D, and the  
introduction of a new class, PrimitivePortrayal3D.  The new class  
hierarchy looks like this:


Portrayal3D
	SimplePortrayal3D
		PrimitivePortrayal3D
			Sphere...
			Shape...  (though it's of course not a Java3D Primitive)
			Cylinder...
			Cone...

More to come.  SimplePortrayal3D has had new AppearanceFor... methods  
added and some more flag-setter methods.  PrimitivePortrayal3D is  
abstract, with a bunch of general methods for its subclasses,  
including the primary getModel(...) method.  The subclasses are all  
relatively simplified.  PrimitivePortrayal3D has some documentation  
that might be useful to you too.

Check out the new balls3d demo, which subclasses SpherePortrayal3D and  
overrides the getModel(...) method in the "new" way so to speak to set  
the attributes and change the size of the spheres.

I'd like to extend this approach to a few more problematic 3D  
portrayals, notably the various edge portrayals and CubePortrayal3D,  
and have asked Gabriel to look into it.

Sean