some questions about the materials system

h3lly3r

Hello!
I've been the last few hours trawling over the documentation, but I can't quite seem to find the answers I'm looking for, and I was hoping to get some help. I'm trying to find an optimal strategy for building my materials for Godot. Does the engine actually use the alpha channel in a normal map for anything? If I'm using the texture and sending that data to the gpu, I might as well use that extra channel for something useful. The same question goes for for an ORM texture, it already has three channels in use, what about alpha?
Another thing is that I cant seem to find an example of using a flowmap for anisotropy anywhere online, other than the screenshots in the documentation, are there any good examples of what this is supposed to look like around?

xyz

h3lly3r Normal maps actually only use R and G, B and A are ignored in the standard material. You can map them to anything you wish but you'll need to do it via a custom shader.

Jesusemora

I'm sorry, what is the question?
Extra channels depend on your material. If you are using the standard material, you must use standard textures, like ARM. If on the other hand you make a custom shader, you can make use of all the channels you want in the same way as the ORM textures.
The engine has a number of inputs for textures, some vec3 like NORMAL, some float like ROUGHNESS. But using more will enable them in godot's mega-shader and have an effect in performance, so don't use them all at the same time unless it's necesary. You can assign a channel with r, g, b, and a in the custom shader.
And unless your texture has an alpha channel, you are not "sending" it to the gpu, it's RGB and it's lighter.

Aniso is an old technology, It's mostly used to simulate metal, but now we have metallic, roughness and normal, which combined can replace aniso. So I would only use it for stylized graphics.
As for the flowmap, Looking online I found this:
https://polycount.com/discussion/98983/how-to-paint-flow-anisotropic-comb-maps-in-photoshop

Good luck.