https://bugs.freedesktop.org/show_bug.cgi?id=83810

Priority: medium Bug ID: 83810 Assignee: dri-devel@lists.freedesktop.org Summary: Blender Weight paint mode doesn't work with enabled VBOs. Severity: normal Classification: Unclassified OS: Linux (All) Reporter: sunweb@hotmail.ru Hardware: x86-64 (AMD64) Status: NEW Version: 10.1 Component: Drivers/Gallium/r600 Product: Mesa

HD 5770, OpenGL core profile version string: 3.3 (Core Profile) Mesa 10.1.3

Download and unpack Blender from here http://www.blender.org/download/ or install from your distrution repository.

Exact steps to reproduce the error:

1) Open Blender and go to File -> User Preferences -> System OR press Ctrl+Alt+U and enable VBOs 2) Go to Edit mode(press Tab) on a default cube and for clear look for both problems(unable to paint and slowdowns) subdivide it atleast a few times(press W -> F6 -> Number of cuts 50*). 3) Go to Weight Paint mode(press Tab -> Ctrl+Tab) and make a stroke, you won't see anything painting and experience slowdowns. 4) Disable VBOs and repeat 2 and 3 steps and everything works and really fast then switch on VBOs again and your paint will disappear but turning off VBOs again will show the one you draw before.

* depending on your GPU the number might be higher. For example on my GPU 20 cuts on a cube won't show any performance decrease with VBOs on thus i am using 50 for more clear look at performance problem.

As described by many users VBOs should make everything faster not slower. And i've checked proprietary drivers VBOs work there but i have different troubles with them thus i am using the OSS one that has a very few non crucial broken features.