I noticed that if I start painting a 3d model, after a while some "white spots" artifacts start to show up, and they become more and bigger the more times I pass a brush on top of them.
Here is the kind of artifact I'm talking about:
What I've noticed is this: Painting on the model directly through texture paint mode doesn't allow you to paint in the whole "image" of the texture that is being produced as you paint. In fact, the brush doesn't even paint on some pixels of the texture file that the UVs are laid on. Check this image:
You can clearly see that part of the UV is laid on a part of the texture image that is white. And it's white because the brush can't paint on there.
Is there a way to avoid this artifact happening at all ? If not, is there an easy way to fix it, other than examining the texture pixel by pixel ? A texture can have millions of pixels, and it's like a fool's errand to try to "hunt" for bad pixels on the actual texture.