Since CTA supports a 3D stage, it would be nice to be able to import 3D objects.  I wouldn't want a complex rendering engine behind it since we are talking a cartoon here.  Just simple support for texture maps and color materials.  And probably no lighting/shadows.  Artists would have to draw their shadows on the texture map which is what we do now for most backgrounds anyway.

Introducing 3D cartoon figures to CTA may also be the answer to making Multi-angle characters being easy to make.  It would be like importing a Character Creator mesh into CTA which acts as a specialized cartoon renderer.  Instead of focusing on a realistic renderer, focus on making the 3D mesh appear to be a 2D drawing.