Every test I've done with VIS_UNDERLAY indicates that it just doesn't underlay the parent icon at all.
Expected Results:
vis child should be an underlay.
Actual Results:
Vis child is an overlay.
Demo project included. My roof objects are constructed from objects with a child set as a VIS_UNDERLAY with a color matrix that makes them appear white.
This white layer should not be visible in the final render at all, but it's showing up over the top of the parent object.
http://files.byondhome.com/Ter13/Rooftest_src.zip
I should be seeing this:
Instead I'm seeing this:
