3 Suggestions for Texture Painting

Texture painting is integral for making any material look good, because it allows you to add variations to a surface, like other textures, roughness, or color variation. However, there are a couple of opportunities for the tools in Blender to be improved.

1: It's fairly common for artists to do RGB masking, where you paint into separate channels for different effects, especially for games. But trying to do that here reveals a few shortcomings that slow down the workflow. So for example, if you want to increase the values of your mask in a place, then decrease another place, and flip back and forth, you have this secondary color option. So if you set these to black and white, you can just press X to quickly switch between them.

But what happens if you turn a grayscale mask into an RGB mask using the image editor? Well, everything I just said assumes you are using the default blend mode, which affects all channels. So for example, let's say you're using the R channel to affect the tint, and the G channel to affect roughness variation. Now when you try to use a green brush, you have to use the Add blend type, or else it will overwrite the red channel, and you can't just use black to take away the strength of the tint, because adding 0% brightness has no effect. So there isn't this quick way to change the influence your brush has on the values of the color channels like there was before.

So, here's my proposed solution. In addition to the secondary color (X), you can also switch between two blend modes (C), or quickly cycle through brushes (V, Shift_V), and switch between two selected brushes (B), assuming those aren't taken of course. You can also toggle what color channels to affect [ R | G | B ] in the top bar, which would enable you to use things like the Soften effect on one channel.

2: I randomly came across a problem where attempting to paint on my model did absolutely nothing, even though I could paint in the image editor. After hours of trying to create a new test image, painting on a UV sphere, and hopelessly trying to google for what was happening, I eventually tracked it down to this TINY little option called Paint Mask, which lets you only paint onto selected faces.

This tool is obviously useful, but my problem was that I had nothing selected. The easiest solution to this confusing problem is to warn in that scenario when you enter the mode or try to paint something, because there's literally no reason why you would want to try to paint with NOTHING selected at all, and wonder why it has absolutely no effect. Now, I did notice a grayed out effect where the selected faces are, in case you're thinking. But first, you may not notice it if nothing is even selected. And even if you do, you won't know why because there's no clue. The only chance you would have of this being useful is if you've already ran into this issue, but for newbies, stuff like this is especially important.

Beyond that, it could also do a similar warning if nothing selected was painted on, which it wouldn't show again until the paint mask has been toggled since.

3: It's fairly common to paint into the wrong texture in Material mode, specifically if you're painting a texture that isn't mapped to the same UV, like if you're looking at the effect it has on a material in render mode. Like if you change something about the material, go back to texture painting, and then you don't realize that as you were moving nodes around, you changed the active image texture to the image node you moved or selected last and then it also affects texture painting. This workflow is fine, although it is fairly weird, especially at first.

Of course you may want to paint into other textures like base color or something. Like, maybe you want to tint the base color, let's say, or paint the roughness? But often, you just want to leave any images alone that are part of a PBR texture set. It's more common to want to paint textures that you've created, like masks. So, if you haven't painted onto a given texture before, a warning could be displayed saying "This texture was imported, not created. Do you really want to paint on it?", then display the name of the image. It could also just not include them by default unless they're explicitly added to Texture Paint mode from a list of image nodes in the object's material. If your active image changed because of a material node edit, perhaps it could warn about that also.