Paint Vertex Color per Channel

[trevor.adams]

(Copied from original User Voice forum)

"Paint vertex color in specified/ isolated channels, for instance: just the Red channel. Right now it's only possible to paint in RGB or RGBA channels . This requires creating extra color sets and then compositing them together making project files bigger and harder to manage."

"The option to use the paint vertex color tool to paint by an individual rgba channel while leaving the other channels alone, just like the apply color tool and its options. Better yet have it work like in photoshop and only see/ work on the grayscale of the selected channels "

[Anonymous]

This option is more useful than we think cause in many game engines you vertex color is it not used as is but rather the single components are painted to transfer data for shaders masks, cloth influences, custom per-vertex mesh information. The vertex color channels are a very suitable for this kind of tasks.

I am looking for the same option and right now the only way to have is it to make my own tool to split/ display/ merge back all the duplicated color sets.

[trevor.adams]

Thanks for the additional info/support @Anonymous!

[Samuel.Couture]

Bumping this. working around this seemingly simple feature that is missing is really complicating the workflow i will have to implement for the results to work and be easily editable

[rkovach]

I've been waiting for this since I started using Maya 6... 🙂

[Anonymous]

This is a must have feature for Unreal or Unity....

[malcolm_341]

Here's a usable workaround I use in Unreal. Use the apply vertex colour tool instead, it allows per channel application, when you're done use the flood fill with smooth turned on in the painting tool to make the single channel verts looks nice, works for foliage and cloth wind painting in Unreal.

[malcolm_341]

Actually, here's an even better workflow, flood fill your object with black, then in the vertex colour painting tool make the colour exactly 1, 0, 0 so you get pure red. Then paint, that should be the same as painting with a single channel, then use pure green, or blue with painting set to add, that should allow you to paint by channel. I just tried it on a quick Arnold layer shader and it seemed to work to paint the channel without affecting the other channels.

[rkovach]

these workarounds are not really that great, you still can't smooth channels independently, or paint alpha without destroying the RGB channels.

there really is no excuse for not having proper per-channel painting features. The vertex color tools haven't changed in 20 years and Autodesk doesn't seem interested in expending any resources to improve them, since they are only useful to a tiny segment of users.

[malcolm_341]

Oh good point, I hadn't thought about smoothing and alpha. Maybe I can create a tool in Mel that smooths independently and paints. We did all our complex painting directly inside Unreal, for cloth and foliage we painted in Maya, but only one channel.

[Anonymous]

2021 and still they didn't do anything to improve vertex paint in Maya 🙂

[malcolm_341]

What features are you looking for, I'm going to create a tool sometime.

[rkovach]

Full support for Replace, Smooth, Add, Subtract, Scale, Remove, Clamp Min, Clamp Max for each individual Channel - Red, Green , Blue and Alpha.

Full support for Replace, Smooth, Add, Subtract, Scale, Remove, Clamp Min, Clamp Max for RGB only.

View the contents of a single Channel as Grayscale values.

Full support for Vertex, Vertex Faces, and Faces.

[malcolm_341]

Thanks, some of that can be fixed with a custom tool in Mel script, but it looks like Autodesk has broken the vertex face colouring options and you'll need to go back to an older version of Maya to access those features. You should log an official bug about the vertex face stuff not working correctly.