Draw manager cache populate happens during Cycles viewport render #63525

New Issue

Brecht Van Lommel · 2019-04-12T09:45:40+02:00

Brecht Van Lommel commented

2019-04-12 09:45:40 +02:00

System Information
Operating system: Ubuntu Linux 18.04
Graphics card: NVIDIA Quadro RTX 6000

Blender Version
Broken: 2.80 beta 0ee23d0f5f

Short description of error
When Cycles Rendered viewport is enabled, the draw manager is still populating the cache for no reason. This likely has a bad impact on performance.

**System Information** Operating system: Ubuntu Linux 18.04 Graphics card: NVIDIA Quadro RTX 6000 **Blender Version** Broken: 2.80 beta 0ee23d0f5f613c4418a3ab2b2c67d47b936350de **Short description of error** When Cycles Rendered viewport is enabled, the draw manager is still populating the cache for no reason. This likely has a bad impact on performance.

Brecht Van Lommel commented

2019-04-12 09:45:40 +02:00

Added subscriber: @brecht

Brecht Van Lommel self-assigned this 2019-04-12 09:46:22 +02:00

Brecht Van Lommel commented

2019-04-13 21:33:18 +02:00

Note this happens even when overlays are disabled. For overlays it needs a depth buffer, but ideally that would not be redrawn every time Cycles renders the next sample.

Cycles signals its needs a redraw with the RE_ENGINE_DO_DRAW flag, so in that case it could skip the depth buffer for overlays, and any other cache population that it might be doing. I'm not sure if Eevee is affected as well, or if it has some way of avoiding the overlay overhead when rendering more samples.

Note this happens even when overlays are disabled. For overlays it needs a depth buffer, but ideally that would not be redrawn every time Cycles renders the next sample. Cycles signals its needs a redraw with the `RE_ENGINE_DO_DRAW` flag, so in that case it could skip the depth buffer for overlays, and any other cache population that it might be doing. I'm not sure if Eevee is affected as well, or if it has some way of avoiding the overlay overhead when rendering more samples.

Brecht Van Lommel removed their assignment 2019-04-30 15:09:28 +02:00

Jeroen Bakker was assigned by Brecht Van Lommel

2019-04-30 15:09:28 +02:00

Clément Foucault commented

2019-05-02 14:49:32 +02:00

Added subscriber: @fclem

Clément Foucault commented

2019-05-02 14:49:32 +02:00

Well we only need to make an exception when overlays are not drawn. This could be a simple check to see if external engine is used and if overlays are off.

Brecht Van Lommel commented

2019-05-02 15:20:20 +02:00

In principle we can avoid the overhead even if overlays are enabled, for Cycles there is no need to loop over all objects for every sample.

Clément Foucault commented

2019-05-02 16:15:36 +02:00

Yes but that would mean caching the result of the overlays to a RGBA texture, which is not how things currently works.

Brecht Van Lommel commented

2019-05-02 16:37:23 +02:00

Ok, that part should not be considered high priority then, or a bug at all. Still think we should fix the no overlay case for 2.80.

If we do that caching at some point it'll also be helpful for Eevee and workbench performance I think, but somewhat less than for Cycles since the object loop needs to happen regardless.

Ok, that part should not be considered high priority then, or a bug at all. Still think we should fix the no overlay case for 2.80. If we do that caching at some point it'll also be helpful for Eevee and workbench performance I think, but somewhat less than for Cycles since the object loop needs to happen regardless.

Jeroen Bakker commented

2019-05-07 09:32:07 +02:00

Changed status from 'Open' to: 'Resolved'

Jeroen Bakker closed this issue

2019-05-07 09:32:07 +02:00

Jeroen Bakker commented

2019-05-07 09:32:07 +02:00

Both high prio changes have been committed. For the cashing we should create a new task.

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Draw manager cache populate happens during Cycles viewport render #63525