Can I have overlapping UV's with a 2-Way Blend Material

The question is self-sufficient, I think, but here’s the details:

I have a wall mesh (modular). One part is wood, the other is stone. I have a stone and a wood texture, both tileable in every direction.

My goal is to texture that mesh with the already existing tileable textures, without adding a new specific texture (saving some texture space)

I have constraints as it is a school project :

  • 1 ID/mesh, so having two UV channels for texturing is out of the question
  • I have limited texture space, so I won’t just do a specific texture for that wall otherwise it means I have to do that for every kind of wall, floor, ceiling, etc. and I just don’t have the space.
  • It’s not a constraint per se, but my teacher recommended me to have (in this instance, as it is in a modular set) 1 mesh that contains stone and wood with a more “complex” material instead of having 1 mesh for the stone and 1 mesh for the wood with 2 simple material. I’ll stuck to those instructions, as it seems logical with what he explained.

Soooo. Can I have my stone part’s UVs take all the UV space with my wood’s part UVs also taking all the UV space, and so have them overlapping with a 2-way blend material ?
I made a test with simple flat colors as textures and it seemed to work fine, but I’m not sure what to expect with normal maps and everything ?

Silly teachers and schools with their silly no-good-reason limitations.
Not allowing a 2nd uv is just plain bonkers.

Oh well, you dont need to unwrap both the wood and stone on the full 0-1 space, you could give each half and just stretch the texture with a texture coordinate node.
You could also make a mask, use vertex color, or many other tricks.
Heck, could forego UV0 entirely with world aligned mapping (more expensive), and more complex ways.
But, yea you can have them overlap and use a mask or whatever to show only one material.

two id’s/materials results in the mesh being drawn/called twice, (drawcalls) so its better to use one material.

Thanks for your answer!
Haha I admit they sometimes have weird limitations, but this time, I think there’s a reason. See, my teachers are honestly very competent (I’m kind of impressed) and I think they just want us to find smart ways to deal with various limitations. Fore example, here, they want us to use the blueprint material smartly, since the main goal is understanding how they work. I do think that it’s a rather good idea, although weird, I admit. Honnestly, I should understand no problem the way to approach this, but due to health reasons, I missed a lot of class and I’m a little behind on that one.
I can use a second UV for lightmapping. It’s really just about the material themselves. They want 1 per mesh. 2 when it’s justified but it must remain rare. My first guess was that it was indeed for the draw/call count.
Vertex color is what I’m using with the 2-way blend. The mask and the “stretching the texture” really interest me. Does that bother you if I ask for more details ?
Anyway, you answered my original question so I’ll mark that as “answered”. Thanks !

I had a few spare minutes so made a video explaining how and what.
It might not be perfect but it might give you an idea on how to go about it.

(might take about 10 minutes after this post since its processing)

Oh my god! That is so nice! Like… seriously. Thank you so much! I don’t have the time to dive into right now, but I will be watching it very soon. Anyway, the main point is : thank you! You rule. I actually have some trouble realising you made a video just to answer my question.

Can you feel I’m grateful? Because that’s what I am: grateful.

I’ve just finished watching and thank you so much. I vaguely remember my teacher explaining that and now it’s super clear and I know exactly what to do. Thanks again! :slight_smile: