On making the Shape class having the ability to add shapes...I don't think it is necessary. I don't even think the VizFrame needs multiple shapes. If I have a reference frame and a point for every shape that I want to be in the scene, then any shapes that need to be rigidly connected to each other can simply share the same reference frame but different points. Adding this extra ability to Shape or VizFrame seems like too much to me. I'd also not worry about boolean operations and all that crap. If people want complex shapes they should have to generate meshes with other software. Our software is not about drawing shapes and we shouldn't waste time on implementing that when so many 3D drawing sofware packages already do this.