Page MenuHome

Object selection so slow it's unusable
Closed, InvalidPublic


When selecting objects in a project with 100k or more faces total, the selection takes upwards of 10 seconds. Problem does not occur on older system. I need to work with several much more complex objects (64-bit is needed) and selecting is so slow that work cannot be completed.

To reproduce:
Open attached project or create one with multiple objects with >100k faces. Right-click to select object. For sample file selecting takes ~6 seconds, but the same action is instantaneous on an older Nvidia-based system. Worst case is when multiple objects are under the cursor position, and gets even worse if more objects exist.

Test system:
Windows 7 SP1 64-bit
ATI Radeon HD 5750 1GB
AMD Catalyst drivers 10.11 and 11.6
Core i7 2600k
Blender 2.58.1 r38019 (64-bit), 2.49b (64-bit), 2.43 (32-bit)

The same problem occurred on all three Blender builds listed. A workaround may have existed for 32-bit versions under older operating systems (see, but there is no solution for the 64-bit versions.

The following older (and much slower) system can select objects almost instantaneously:
Windows Vista 64-bit
ATI Radeon HD 5750 1GB OR Nvidia geforce 8600gts 256MB
AMD Catalyst drivers 10.11
Core 2 duo e6750
Blender 2.58.1 r38019 (64-bit), 2.49b (64-bit), 2.43 (32-bit)

Had trouble submitting this bug with a large .blend file, so I am re-submitting without it.



Event Timeline

It is regrettable but really out of our control if 3rd party vendors release poor drivers under certain configurations (amd/vista/64bits in you're case), ATI/AMD has been known to have poor selection performance for some time and while I was under the impression they improved this recently, it seems not in all cases :/

Can only suggest to try different configurations or update you're hardware (recent win or linux for example) but understand changing you're OS only because of a bad driver may not be practice for you.

Selection works fine under Vista, it's Windows 7 that seems to be the problem using the same video card and driver version. I submitted this to make sure you're aware that selection doesn't work well on NEW hardware and software. The reason I am using the Catalyst 10.11 is because there is display corruption with the newest drivers (when using mouse in 2.49b and intermittent in 2.58a).

Any suggestions for a video card that would perform well?

Selection for high-poly objects has recently become annoyingly slow under
Ubuntu 11.10 64bit (with Xfce desktop)
kernel 3.2.0-37-generic
NVIDIA proprietary driver 304.64-0ubuntu1~precise~xup

At one point in time I thought it was a Blender update, as it seemed to me that Blender 2.63 or so was still fast while a more recent version became slow, but now it's all the 2.6x versions that are slow. Still not sure whether I actually had a version-specific slowdown.

Anyway, it has become unbearable by now. To demonstrate the slowness, I start with an empty scene, add a Suzanne, give her a Subdiv Surface Modifier with display level 2, duplicate her a few times, and try to select. At this subdiv level, I wait for ~3 seconds until Blender becomes responsible again. Increasing the subdiv level quickly aggravates the problem.

Browsing the web, I arrived at the suspicion that modern OpenGL drivers now do do in software (glRenderMode(GL_SELECT) or the like) what they previously did in hardware. I do not know whether Blender uses glRenderMode. It surely did way back then...

Yes, it is the driver. blender-softwaregl is rendering a bit more sluggishly, but selection ist certainly good enough.

Do I have to report a new bug, or can you reopen this one?

After quite a few new versions of the NVIDIA driver (I'm at the forefront of what Ubuntu gives us from NVIDIA) and Blender versions (2.69 currently), the selection delay on complex models in the 3D object view is still unbearable. I've adjusted my workflow to use the outliner, and when I accidentally slip into mouse selection, I curse and wait...

Blender team, please tell me whether anybody is working on the fix of this, whether there are any patches, or whether it makes sense to actually try to develop it myself - I'm familiar with using glRenderMode(GL_SELECT); finding the right method for newer OpenGLs and the current Blender code is something that I would really try to start with now since the selection situation has turned into a major PITA.

The selection topic costs me a lot of time with ubuntu and blender up to 2.69
At least I can confirm that switching to 2.72 and enabling "Occlusion Queries" changes the selection behaviour from (30 seconds to immediate selection)

@Andreas (woody64), JFYI, we're about to release Blender 2.75, if you're still using 2.72 it might be worth updating ;)

From the link:

OpenGL Occlusion Queries (User Preference)
See User Preferences ‣ System ‣ Selection

This option defaults Automatic, try setting this to OpenGL Occlusion Queries, since there is a significant performance difference under some configurations.

This solution worked for me.

For Intel i5 onboard GPU this also fixes the problem.

Seems like It also fixed the problem on Intel i7, Kabylake.