Created attachment 151753 [details] Example brushstrokes SUMMARY When using a "grungy" brush tip with a lot of texture detail, it is apparent is that the brush behaves very differently at different sizes. Strokes drawn at small brush sizes are fainter than those drawn at large sizes. Using auto brush spacing doesn't seem to help. My guess would be that the algorithm used to scale brush tips doesn't maintain the average value of the brush tips, and instead ends up lightening the tip when scaling down. STEPS TO REPRODUCE 1. Create a brush with no opacity, flow etc. dynamics on. 2. Choose a highly textured brush tip, such as "DA_Oil stamp 02" 3. Set flow of the brush to 10% 4: Draw a stroke with a 5 pixel brush and another with a 15 pixel brush OBSERVED RESULT The lines are perceivably different in value EXPECTED RESULT The lines should be roughly similar in value ADDITIONAL INFORMATION I have included a screenshot with examples of the results I get and an example of what I would hope to get, created by scaling a 15-pixel brushstroke down to match a 5 pixel stroke.
Created attachment 151823 [details] screenshot of my attempt at reproduction I cannot reproduce this: this looks like the small line was painting with flow 10%, and the bigger line with flow 100% -- and then the difference is expected. If I paint with flow 10%, both lines are equally grey, with 100%, equally black
Setting to needsinfo
Created attachment 152019 [details] Demonstration brush
(In reply to rebuilderster from comment #3) > Created attachment 152019 [details] > Demonstration brush I've added a demonstration brush, this should reproduce the issue if you compare 5 vs 15 px strokes made with this brush.
Thanks, that's very helpful! I will test this later on.
I can confirm with the Krita Version: 5.2.0-prealpha (git 5c98a72) Appimage with Qt 5.15.7 and the attached brush bundle. Thanks!
Created attachment 158219 [details] Screenshot of the rectangle Auto brush tip test with 3.0 auto spacing and 7% flow The brush tip's average value is actually correct. The brush tip's values variance is not - it gets progressively lower (meaning that all pixels are getting closer and closer to the average, meaning some medium grey/half-transparent). However, the fix for the variance doesn't fix this issue (I checked). The specific issue with this brush is just caused by Auto spacing + very low Flow. If you follow those steps: 1. take the demo brush 2. change the brush tip from "Predefined" to "Auto", then change to black square 3. Paint with it on 5px and 15px. Result: the same bug, despite no brush tip image being scaled. 4. Change the Spacing from 0.02 to 3. You'll see that in case of 15px, the brush tips overlap, but in case of 5px, there are spaces between them. The objective value of the spacing does get smaller, but not small enough.
Remove triaged keyword from CONFIRMED bugs