Hi all. I'm a long-time Paint.net occasional user - I'm no artist but it's my go-to tool for rough work or mockups.
Anyway, I want to paint on a layer in an additive way. i.e. I set a color like (10,0,0) and if I hold down or repaint an area, it gets brighter and brighter. The idea is I want to create a texture map for a 3D model, which encodes how thick the material is based on the red channel.
But I can't seem to get this to work. I tried using (255,0,0,10) i.e. red with very low alpha and that sort of works, in that it looks right on screen, but it's not outputting as I expect/desire when I save to a flat file like PNG/JPG.
Any advice both on the exact question I've asked, and how better to do what it is I want, are welcome - there could be a much better way I'm not aware of.
Thanks.