[planteen]

Keep in mind that GPUs are asynchronous. So with WebGL, you send a series of draw calls to the GPU and don't have a way of pulling a result out early. Some extensions for OpenGL ES let you preempt for another rendering task, but not sure if that would help you.

Your clockwise idea doesn't make a ton of sense to me. You typically have a depth buffer enabled in 3D and draw your scene in a front to back fashion. This lets you save on evaluations of the fragment shader for meshes that are occluded.

I guess you could sort draws in your clockwise spiral and synchronize after each one, but that is going to be a massive performance drag since the GPU can't pipeline draws anymore.