ucupumar
commented
4 days ago I'm sorry but I can't accept this PR, Ucupaint already has a better way of handling alpha. You can enable the alpha in the main channel settings.
You can see various demos of channel alpha here:
- https://ucupumar.github.io/ucupaint-wiki/01.01.channel/#rgb
- https://x.com/ucupaint/status/1790353019877671383
- https://x.com/ucupaint/status/1792134005548274044
Alpha should be tied to the RGB channel because the RGB value should be divided by alpha when doing the blending process. Without this, the transition between 0..1 alpha will have incorrect color.
Users can of course always create a dedicated alpha channel like you did here, but it should not be included in the first preset since there's a better way like I mentioned before.
It's common for game assets to have transparency (glass panels, fences, etc), and being able to control alpha through a separate channel is convenient so it makes sense to have this button. GLTF exporter picks it up with no problem, tested this workflow with Godot
P.S. GLTF also has support for emission which can be useful in texture sets, I'll test the support for that with GLTF in Godot later as well and open another PR. Then ucupaint will properly support the regular gamedev texturing pipeline