General question about textures

beach07

Hi everyone,

I recently started dabbling with Unreal 4 and Substance Painter and came across something that I don't know much about, so I came here for an answer. Basically, I'm working on a mesh with multiple objects and therefore requires multiple materials. In Maya I have separated my mesh by assigning different materials to each object so that when I import into Substance, I can isolate the different areas and work on them without affecting the others. Now when I am ready to export, each object in the mesh has its own set of textures. I'm simply wondering if this is okay to have. From what I have seen, a single mesh always has 1 set of textures. It seems like it would be a waste of space to have multiple texture sets when each one only has a small amount of texture information.

Thanks in advance for any info.

Eric Chadwick

It depends on the model. Can you show a pic of what you're working on?

Most models are a single material because this reduces draw calls. Each different material requires more draw calls, which can slow down the framerate when there are too many.

However sometimes it makes more sense to use multiple materials. For example if you have some transparent bits, like hair. Transparency can be expensive to render in a game, so you would use two different materials for an animal.

Those two materials could certainly share the same texture atlas. One material would use the alpha channel for transparency, the other would ignore it.

However if you're using an alpha channel to define transparency, and the texture is large, this can significantly increase the size of the texture in memory. It may be better to split the hair texture into its own smaller bitmap with alpha, and remove alpha from the large no-transparency bitmap.

I hope that makes sense.