Selecting NON-RGB colors in a Color ID mask for material blending

Unreal Engine Asset Creation
#1

So I have a asset with more than 4 materials on it, I am curious how to select the colors that are not R,G,B, or the Alpha for blending.

So lets say I have a Red, Orange, Yellow, Green, Teal, Blue, etc. How would I select the Orange, Green, Teal for a material blend?

I searched around and I found this thread on Polycount but no-one went into the detail on how they got more than 4 materials to blend.
http://www.polycount.com/forum/showthread.php?t=99335&page=32

I figure I can just create 2 seperate color ID masks, but that’d be a waste of texture space.

#2

Bump , very useful . Someone did it work?

#3

If you’re looking for on/off (no alpha blending), then you can have 256 materials just by using each RGB value for a different material.

If you want to blend them, then you’re out of luck because Cyan is a mix of the Green and Blue channels from RGB, and there’s no way to tell whether you meant to mix the G and B textures, or if you wanted the Cyan texture… And even then, no way to tell what you wanted to blend the Cyan texture with.

#4

Wouldn’t you be able to take the specific blend mask of the G and the blend mask of the G and blend them using the “add” node?

#5

Well, technically there’s a way. Softwares like Substance Designer can extract any shade of a Clown Mask (Color ID Map) and apply it’s transformations on it.
I guess there should be a way to create a node that act like “Threshold” but for a Float3 instead of Float1.

#6

I’ve made this material function that works fine for me
0254b64e0062f9ca55a2e1f0298f07309c670843.jpeg

Hope this help, if someone need more info fell free to ask!

Christian Ronchi
www.chricchio.com

#7

making a dot product betwen the texture and the desired color will give you a mask. apply a power node to that and you can adjust your threshold(dont forget to clamp the result). not perfect, but easy and fairly cheap.

#8

Hi Christian,
Thank you for posting this. It is exactly what I’ve been looking for. Can you explain your node flow here? I understand the majority of it, but I am not sure what nodes you’re using for the “Input ColorID Texture(Vector3)”, "Input Color Masked (Vector3), and the “1-x”. I appreciate any help you can give me!

#9

You might find it useful to have a dig through these functions I made:

You might also benefit from this function I made. It’s like an ‘if’ node, except you can have a ‘soft’ blend, it supports RGB inputs, and is a **lot **cheaper than using three ‘if’ nodes. (I haven’t checked it in a while, you may have to open it and set the ‘gradient input’ to vector3 to get it to work with RGB)

#10

If anyone is still looking for a way to use a color ID mask in Unreal you can find a color ID mask function (any color) as part of Extile’s non repetitive tiling material here:

Short video on how it works:

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