Oh I agree that it would be nice to scrap most of VoxelSystem and replace it with an improved renderer, and I also agree (as you'll see in the email I sent you) that I'm bullish on the concept you've started here with your PrimitiveRenderer class...

That said, I also agree that we need to do this work in a stepwise fashion that allows this code to coexist. 

Let me think about this a little more, there may be a way for us to make the new primitive renderer a wholesale alternative to VoxelSystem that can sit side by side and only operate when enabled, so we can evolve it to be fully functional until switching it over.

In general the VoxelSystem is really just a wrapper for the local VoxelTree that knows how to render it, other than the fact that the Application classes don't directly access VoxelTree... the VoxelSystem doesn't really anything other than handle rendering of the local voxel tree.