DecalSet for a lot of decal materials

I have a mini-game for my game in which the player has to paint a lot of decals. The decals are randomly chosen from a pool of images. Problem is, a DecalSet can only hold a single decal material, and that left me creating a lot of DecalSet components whenever I want to paint a decal, because the decals are different and not using that same single material. Performance considerably dropped down.

0 decal:

50+ decals, the time spent during Render/Present increased a lot:

Is there any workaround? I know I can customize DecalSet into something else, i.e. LightDecalSet which optimizes for only one decal, but I’d like to know what I’ve been missing.

Thank you!

Maybe back them into the atlas?
Do you really need multiple materials, or just multiple textures?

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Or use a texture array if it’s just the textures you care about and tweak the shader so you can use UDIM or your own convention.

Arrays are less hassle than texture atlases but do require all decals be the same resolution.

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Thank you both @Sinoid, @Eugene for your suggestions.


Yes, what I really want is multiple textures. But I totally forgot about using atlases, thank you! So I packed up all my textures with SpritePacker and manually specifying UV coords during DecalSet::AddDecal() to only paint what I need. That works wonderfully, and I don’t have to deal with having to create a crazy amount of DecalSet anymore.

It surely performs better than the last time, scoring 70+ fps with 90 decals, performance loss is minimal:

@Sinoid I digged the documentation and it seems like Urho has some sort of support for texture arrays (Texture2DArray), but I’m pretty confused on how to use it. Was it the texture array thingy you were talking about?

  1. Make texture array resource combined of all needed textures.

  2. Make custom shader that is able to sample these textures according to some ID

  3. Somehow pass this ID along with decal into DecalSet


  • No edge bleeding issues


  • Harder to maintain
  • Same texture size for each texture
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Alrighty then, I guess I won’t be touching that anytime soon, I suck so hard at shaders XD. The atlas solution works great atm and that’s just fine by me.