The issue is only skyboxes and huds can be drawn, without zbuffer support any model with overlapping parts will not render correctly.
The solution although not documented well is to use a more complicated multi-pass rendering system where the zbuffer but not the rgb-backbuffer are cleared between passes, and all objects are parented off either a near medium or far pivot entities that can be shown/hidden to perform the trick.
The solution although not documented well is to use a more complicated multi-pass rendering system where the zbuffer but not the rgb-backbuffer are cleared between passes, and all objects are parented off either a near medium or far pivot entities that can be shown/hidden to perform the trick.