Short version of the question is: how do I pick through the transparent parts of a GUI Plane that is in world space?
Refer to this PG: https://playground.babylonjs.com/#FXFTTV#3
Starting on line 32, I am creating a Plane and an Advanced Dynamic Texture so that I can render a UI that lives in world space. You will note that in my example there is a lot of transparent space between the buttons. What I need to do is pick up UI events (hover, click) on the buttons but allow pointer events to “pass through” the transparent spots on my UI plane.
In the PG example you will note that you cannot pick on the sphere (because it is behind the UI Plane).
If I set the ui plane to isPickable=false then I no longer pick up clicks on the buttons. Setting bg.isPointerBlocker = false does not seem to do what I need either.