I only know of 2 image textures the ones used in Transparency which is black & white, and those used in Normal Maps which look like blueish, violets.
I don’t know where to use the Yellow with Green and Red Texture.
If you are referring to the basic, diffuse color for an object, you connect to the base color/color input in a shader.
hi Phil_n. thanks for the reply. what i meant was this type of image texture: (i’m pretty sure it’s not a diffuse texture because i have already the right image texture for it)
Probably AO, roughness, metallic in RGB channels respectively. (Well, nothing’s metallic, so…)
i think roughness and metallic image textures are also in grayscale color. not sure about ao though
If you separate your rgb with a convert separate RGB. Every channel will be b&w.
thanks, but what i would want to know is what image data is the image above? is it a specular map, a metallic map, or something else?
I think they mean more than one type of map has been stored within one RGB image. An RGB image is effectively giving you three greyscale channels which can each store a different thing.
In your case the Red channel is for all intents and purposes pure white, the Blue channel is 100% black and the Green channel contains the most information
2 Likes
The other posters have it, I think., though It might be helpful to know where the image came from (for instance, a “game-ready” asset). As mentioned, for game engine shaders, it is often useful to combine multiple grayscale images into one RGB image. Unfortunately, there seems to be little in the Red and Blue channels (Red being all white, and Blue being all black [note: if you crunch down these channels using something like Photoshop’s Levels tool, thee is info there, but it coincides with the Green channel]). Looking at just the green, it might be an AO map given the shading of the image.
Added:
Couldn’t a game developer using a certain game engine also rewrite the engine to interpret maps in a specific way? I.e. in the red and blue channels, maybe what is shown is roughness and spec maps, which has certain bits of the map reserved to describe things like anisotropy, anisotropy rotation, and metallicness which might be applicable to certain assets (not a face)? While still managing the same number of maps I mean. Albedo, normal as color/3ch maps, then the rest - aniso, anisorot, metallicness, roughness, spec/ior, AO - packed into a single 3ch 8bit image.
Would be confusing if all you get is the image, but if you had the tool reading/managing/combining it it would make sense. Wouldn’t it be up to the game developer how the game engine is used?
The first thing I was thinking of when I saw red/green map, was a UV flowmap. But this clearly isn’t it.
1 Like
Yes you are right. In unreal for example regarding certain hardware with older Gpu whe have to rewrite the way the shader are or the shadows are or what else for sharing the resources in between cpu/Gpu for example or reducing the vram or ram occupation. Imo here is for the face. Roughness sss et spec
This is certainly a possibility. I presented this information for reference, not as an answer. My initial instinct said there was no information in the R and B channels, but as maps, all white could mean “everywhere” and all black could be “nowhere.” The R could be for SSS (everywhere, equally), and the G could be for metallic (none).
I also know that images that seem to be a uniform color in an image editor could have mathematically significant information, and so I boosted the contrast to see. Seeing that there is information in R and G only where there is also information in B (and that it is the “same” info, just inverted) leads me to think that this info is coincidental.
With the given information it is hard to determine, but that is why I was asking where the map came from.
Some render engines like Arnold and Redshift have 3 sss inputs for their skin shader, like Shallow Mid and Deep scatter. Usually it’s 3 different textures with color information, but I suppose other engines could use just the b/w values of each channel for area of influence. Seeing how the texture is mapped to a face I think it might be for that use.
But like the people above mentioned, can’t say for sure unless we know the origin of the map.
I have the same problem figuring out what information the image texture contains. I am facing some game assets with random file names. Is there any systematic way to figure out?
The systematic way is to contact the person that made the texture, or the person that wrote the shader that the texture was built for, and ask them, or to read the shader code if it’s publicly available.
Thanks for your suggesions. I downloaded the model with the texture from Internet. I will have a try.