Created attachment 190321 [details] Video of speed linked to size, quick movement SUMMARY Brushes using 'speed' modifier have detection patches where they appear to think brush move very slow - means that any brushes with variant based on speed are rather unusable. See video for obvious example with speed linked to size. I am using Samsung tab s9 ultra, with 16gb ram and snapdragon 8 gen 2, which does not experience slowdown in other areas of the app. Pen speed does not have the issue in other drawing apps, so I believe it is a krita issue. STEPS TO REPRODUCE 1. Make brush with a factor linked to brush motion speed 2. Use the brush at fast speeds 3. See patches of detected low speeds OBSERVED RESULT Jittering in brush thickness when linked to speed, with larger blob appearing as if brush is slowing for split second EXPECTED RESULT With brush used in example, should be consistently smaller at faster speed SOFTWARE/OS VERSIONS Windows: macOS: (available in the Info Center app, or by running `kinfo` in a terminal window) Linux/KDE Plasma: Android, Krita 5.2.16 KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION Can't copy Info from the bug report tab as it seemingly gets saved to krita's built in clipboard, not the global tablet clipboard - thus cannot paste the text outside of krita app
I can confirm this issue. The problem seems to be that the tablet history is incorrect again, since disabling Settings → Configure Krita → Tablet settings → Disregard tablet position history makes the problem go away. I guess all the historic events just get assigned the timestamp of the last event and so it seems like the brush is constantly speeding up and halting entirely.
Git commit e451439bfa053d01e2fb236f9c5155998bf56ecc by Dmitry Kazakov, on behalf of Carsten Hartenfels. Committed on 09/03/2026 at 10:00. Pushed by dkazakov into branch 'master'. Disregard repeated positions in speed smoother Because they are almost certainly garbage. On Android, these occur all the time with historic tablet positions and lead to the speed lurching if they are not ignored. M +7 -2 libs/ui/tool/kis_speed_smoother.cpp https://invent.kde.org/graphics/krita/-/commit/e451439bfa053d01e2fb236f9c5155998bf56ecc
Git commit 37fc743c21864852d47cb19cb4f5442a720914e4 by Dmitry Kazakov, on behalf of Carsten Hartenfels. Committed on 09/03/2026 at 10:00. Pushed by dkazakov into branch 'krita/6.0'. Disregard repeated positions in speed smoother Because they are almost certainly garbage. On Android, these occur all the time with historic tablet positions and lead to the speed lurching if they are not ignored. M +7 -2 libs/ui/tool/kis_speed_smoother.cpp https://invent.kde.org/graphics/krita/-/commit/37fc743c21864852d47cb19cb4f5442a720914e4