I wish the new OSA de-optimizations could be turned off

Rendering a sample scene [a cube over a plane] with ambient occlusion in the 2.33a release and 8x OSA turned on, takes 17 seconds.

In the new 2.34 release, rendering the exact same scene takes 1 minute, 30 seconds. Those optimizations were nice, even if sometimes leading to very slight artifacts. I wish there was an option to re-enable them for raytracing if so desired. :frowning:

There is no difference in the final output. With complex scenes, yes, maybe a magnifying glass and a sharp eye can spot some flaws in the optimized OSA. But Such a huge ballooning of rendering time to remove such minor imperfections is very bothersome, as there is no option to turn it off.

The sample scene I used is here (although you could make your own in about 20 seconds) Just render it first under 2.33a and then under 2.34, and you will see the difference immediately.


I agree there is a rendering time increase but I have found that if you use the Unified Renderer in 2.34 the time differences are not that great. Also using GUASS OSA filtering seems to be maginlly faster.

Here are my tests.

Version 2.33a - Unified Renderer
NO OSA - 18.77
OSA Level 8 - 21.64
OSA Level 8 No AO - 3.91

Version 2.34 - Unified Renderer
NO OSA - 19.15
OSA Level 8 - 27.52
OSA Level 8 No AO - 6.83

Selecting the unified renderer really helps. Thanks for the tip!

I wonder why this is so? I had always previously read that the unified renderer was slower then the default renderer. It’s whole purpose was to turn off certain optimizations. Now it seems to have the opposite effect. Oh well…

My new 2.34 time is 23 seconds. Going from 17 to 23 seconds doesn’t seem merely so painful a loss.

Glad I could help.

I have no idea why its changed, maybe one of the developers might be able to give us some idea. :slight_smile: