SUMMARY "Press middle mouse button and move to scroll" option interfears with the normal functioning of blender, specifically instead of rotating the camera as it should it causes the camera to zoom in or out. In addition when trying to use the middle mouse button to rotate in blender it results in the mouse wheel not functioning normally in all programs afterwards until display-manager is restarted. After causing the bug in blender when scrolling in any program afterwards and then scrolling in the opposite direction the first scroll in the opposite direction will not register. The bug presists until display-manager is restarted even after blender has been terminated. STEPS TO REPRODUCE 1. make sure "Press middle button and move mouse to scroll" is checked in system settings under mouse options 2. open blender (https://www.blender.org/ or just install it with your package manager) 3. hold middle click (the scrollwheel button) to try to rotate the camera and move the mouse forward and back. This will result in the camera zooming in and out instead of rotating as it should. 4. Now close or tab out of blender and open firefox or your preferred browser or anything that you can use the scroll wheel to navigate up and down with 5. Scroll down, then scroll one tick upward, that tick should be ignored and not register for some reason. Subsequent ticks upward should register. 6. Scroll down again after having scrolled up, the first tick of downscrolling should not register and be ignored for some reason. OBSERVED RESULT One tick of scrolling is always ignored when switching scroll directions and trying to rotate the camera in blender results in zooming instead EXPECTED RESULT Rotating the camera in blender with the middle mouse button should work without issue and should not result in a subsequent system wide screw up of the mouse scroll wheel. SOFTWARE/OS VERSIONS Operating System: CachyOS Linux KDE Plasma Version: 6.3.3 KDE Frameworks Version: 6.12.0 Qt Version: 6.8.3 Kernel Version: 6.14.0-4-cachyos (64-bit) Graphics Platform: X11 Processors: 8 × AMD Ryzen 9 7950X3D 16-Core Processor Memory: 61.9 GiB of RAM Graphics Processor 1: NVIDIA GeForce RTX 4070 Ti Graphics Processor 2: AMD Radeon Graphics ADDITIONAL INFORMATION
I'm not able to replicate any of the buggy behavior on Plasma 6.3.3 or git-master. I'll leave this open in case someone else can replicate.
KWin is responsible for input; moving there so the KWin folks can triage it. I vaguely recall another report like this in the past being closed as a Blender issue, but I'll let them make the call.
Actually since you're on X11, this may even be an X server issue.
So it would be good to know if it happens on Wayland too. Can you check?
Just tried it on wayland, it's bugged on wayland too but not in the same way, if you have use middle mouse button ticked on wayland it rotates but only on one axis (left and right or up and down) and also doesn't subsequently bug the scroll wheel until the display manager is restarted
That is the expected behavior of the option, yes. Middle click dragging is replaced with scrolling. We unfortunately don't have any further control over the option, nor information about whether or not the application wants to do middle click dragging itself, so that part can't be changed as it is right now. I think the right place to report the problems on Xorg is https://gitlab.freedesktop.org/xorg/driver/xf86-input-libinput/-/issues