Texture Paint won't paint the whole face - Bleed option seems to be off recently I've wanted to test out the Texture Paint Mode on Blender with some simple model (low poly stuff). I've been able to correctly (I assume) UV unwrap -manually and smart unwrap- my model to prepare it for texture painting. However when actually painting the model I've noticed some issues, whether trying to paint with a brush tool or the fill tool, some very small areas of faces of the model, whether having Face Selection Masking enabled or not, could not be painted:



I'm currently trying to paint on a 512x512 texture (don't know if the size matter) but, when trying to solve this problem, even with a resolution of 4096x4096 this problem still occurs, although it is less visible. I've also tried to mess around with the Bleed value by increasing it a little bit (from 2px-4px to 8px), and when I did that I noticed something else:



It seems that the "paint" is being applied with some rotation to it, and I don't think this is the expect result, so this might be the source of my problem.

Blend File
Indeed it seems there's been a regression since 2.76. I reported it here https://developer.blender.org/T52453

Meanwhile, here's how the bleeding algorithm works on triangles :



this explains the non parallelism between the UV edge and the bleeding edge 

since the regression, the bleeding treats a quad as 2 triangles.

In any case, most of the times, the best method is to not use bleeding, but paint on a transparent image, export it, import it in the compositor and feed it through an Inpaint node. This gives an even thickness and prevents bleeding in other islands or inside the same island.