Have one object Matte another object

[babylonchaney]

Moved importing mesh issue to a new topic:

Imported mesh not working with disableColorWrite

I have tried numerous meshes locally, including a simple cube, but imported meshes do not seem to respect the disableColorWrite material or onBeforeRenderObservable/After for masking another mesh. I have a playground here: https://playground.babylonjs.com/#Z3GIKS Uncomment lines 52&52 or 56&57 to attempt masking with imported mesh.