Substance material discoloration

Development Rendering
1

Hello, I’ve got an issue involving Substances and Layered Materials, illustrated below:

The left wall has got a regular Substance material applied. The right wall utilizes a Layered Material (shown below) running through two MatLayerBlend_Standard nodes with masks, first for the shape of the window, then the shape of the pattern. It’s then run through a MatLayerBlend_BakedNormal with a blended normal map for the pattern. To get the materials for the wall and the pattern I’ve turned them into Material Functions, using Substance textures, and run them through the MatLayerBlend_Standard nodes.

The whole point of the setup is to be able to mask out the shape of the window and apply the transparent window material so as to avoid using a bunch of extra polygons in cutting out the shape of the window on the actual mesh. I’ve also set up some things as parameters because I’m reusing the pattern masking part of the network to apply different patterns on other, square windows. These windows are separated in the actual mesh with unique MatIDs, so they don’t require the window masking part of the material setup.

As I was writing this I also tried pulling out a Point Light to check a suspicion I had (shown below), since I only had a single light source in the scene, and noticed the windowed wall seemed to only inherit the base color from the Material Functions, not the Normal or Roughness channels. I tried running the Material Function for the wall material directly into the output to fix this, but it still only displayed the base color channel.

I’m stumped. Anyone got a solution, alternatively another way to go about it entirely and achieve the same result? It’s very likely that I’ve needlessly overcomplicated things somewhere (or everywhere), since I’ve only recently gotten into these more complex material setups in Unreal and my head is kind of swarming with a bunch of cool ideas I wanna try out.

2

What is the problem you are having exactly? It is very hard to tell from the images that you posted as things look correct. Also, polygons are super cheap to render so you might be better off making the windows our of mesh instead of trying to make a complexe Material for them as that will end up costing more. Rember, vertices are cheap to render but pixels are not.

3

Sorry that the images were unclear: my issue is that the wall material I’ve masked out on the windowed section is supposed to be identical to the material applied to the plain wall on the left side, sharing textures generated by the same Substance instance. The discoloration on the windowed section seems to occur because the wall material for the windowed section (set up as a Material Function with MakeMaterialAttributes) doesn’t seem to be inheriting any information from the normal and roughness maps I set up in the material function.

I probably am going to just edit the mesh as you suggested to separate the window. I’m still interested to know what’s causing the discoloration though; if nothing else just in case I’ll need to do something like this some other time.