Slow VFB

[dj_buckley]

Not sure this is a bug or just an innefficient feature.  But the tone mapping stack responds really really slowly if you have a Curves operator expanded in the stack to show the histogram.

Turning on and off different operators such as Contrast and Tone Curve take forever to update in the render window, until you collapse the curve operator so the histogram isn't visible or get rid of it altogether.

[Aram Avetisyan]

Hi,

A video recording would really help.

Even with three curves operators expanded (there is a known bug for expanding similar operators), turning any (including curves) operators is fast as expected.
Please attach enough information to better understand the issue.

[dj_buckley]

Here you go - https://drive.google.com/file/d/1FIWePCxhubwWXmP2lN_RQqjPdpNJCGqN/view?usp=sharing

That clearly demonstrates how sluggish the response is after adding the Curves operator and having it expanded.  Without Curves it's instant, with curves I have to wait for it to catch up when making a change

If it helps, the workstation is i'm working on an i9 13900KS, 192GB RAM, 4090 GFX Card

[Aram Avetisyan]

On a production scene, with exact operators and values as you have, and with 4000x4000 resolution:

E.g. contrast operator turning on/off is not as fast as with lower resolution, but having curves enabled or disabled, with histogram, did not result in any change.

So this is either scene or hardware related.

Can you please tests and see if there is slowdown with lower resolutions, and with the default operator stack and then curves at the end?
Please try with VFB 1.0 too.
If there will still be a slowdown, I think we will need the scene to investigate it further. But I am not aware of many "slow VFB 2.0" reports.

[dj_buckley]

So this is either scene or hardware related.

Can you please tests and see if there is slowdown with lower resolutions, and with the default operator stack and then curves at the end?
Please try with VFB 1.0 too.
If there will still be a slowdown, I think we will need the scene to investigate it further. But I am not aware of many "slow VFB 2.0" reports.

Interesting, I do remember there were issues with the curves operator in VFB 1, I think I was the one who found it (https://forum.corona-renderer.com/index.php?topic=40316.0_ and you guys agreed it was an issue after initially not being able to replicate it, I was also using different hardware back then, this appears to be the same thing, but unfortunately I don't have time for all those tests.  I am happy to send the scene over though.

[Aram Avetisyan]

No problem.

You can submit through: https://support.chaos.com/hc/en-us/requests/new

Please mention the forum thread also to keep better track of things.

[dj_buckley]

No problem.

You can submit through: https://support.chaos.com/hc/en-us/requests/new

Please mention the forum thread also to keep better track of things.

Done Request #283763