[POM] Textures with heightmaps self shadow even though there is a decal on top of it

[xoxor4d]

Describe the bug

A base layer with pom applied + decals on top cast shadows onto themselves, which are visible through the decals even if the decal has an opacity of 100%.

The decal layer also has a heightmap applied. That heightmap isn't visualized by the debug view

To Reproduce Steps to reproduce the behavior:

1. Add heightmap to base layer
2. Add heightmap to decal layer

Expected behavior

• Decal layers should scale self shadowing of the base layer by the opacity of the decal layer?

Screenshots

https://github.com/NVIDIAGameWorks/rtx-remix/assets/45299104/fdf8a4a1-38df-4f92-a0db-c221b9e2b00d

[MarkEHenderson]

REMIX-3080 for tracking

[Safemilk]

I closed #641 as it's a dupe of this one. Thanks @xoxor4d .

Curious if there has been any progress on this? Vampire uses a TON of decals as well and it's a pretty noticeable issue throughout the game as I go along replacing the materials with POM supported ones.