EIS Adaptive - problem

[Robert]

I encountered a problem when ever EIS is set to adaptive and there is one direct light in the scene. So same animation scene rendered fine with adaptiv on (EIS) and no direct light. But once I turned it on I got heavy flickering coming from the direct light (clearly to identify in the Channel Output for direct light). It looked like the direct light was sampled to some low res texture and projected. I got huge squares in the the channel that caused that flickering, and of course it then affect reflection and other layers. Turning EIS adaptive off did fix it.
Now I read that this feature require Lights to be set to Adaptive mode too, which is on by default. And was also on in my scene. I don't get it, how should I deal with that in the future?

[vladimir.nedev]

The "huge squares" thing sounds like an issue with the adaptive dome light, which of course is disabled when you disable EIS.
Are you on the latest nightly build ?
Can you show some screen shots ?

Greetings,
Vladimir Nedev

[Robert]

Yes, latest nightly.
Here are screenshot. Its not easy to decide as VRay RT doesn't show it. And its just part of the final rendering. You see it mostly in animation, and they its really heavy.
All settings are set to default. GI is brute force/Light cache. I think I had local sampling on. But, that again seems not be doing any difference.

Sample shows the direct light output. You notice it only lightly on the RGB output. Its almost invisible in a single image, but like in my case with many columns it flickers like a disco ball.

[boyan]

Yes, latest nightly.
Here are screenshot. Its not easy to decide as VRay RT doesn't show it. And its just part of the final rendering. You see it mostly in animation, and they its really heavy.
All settings are set to default. GI is brute force/Light cache. I think I had local sampling on. But, that again seems not be doing any difference.

Sample shows the direct light output. You notice it only lightly on the RGB output. Its almost invisible in a single image, but like in my case with many columns it flickers like a disco ball.

Hey, Robert,

Thank you for the feedback. You can fix it by changing LC with BF or Change the Adaptive to Full Evaluation. I'm suggesting the first one to you. You might check the incompatibilities of DR server but basically, if you change the LC with BF it will fix the problem.

Cheers,

[Robert]

Yeah, that's only logical. However in the manual docs for 4.0 you write: Adaptiv works best with LC... wrong hint I guess.
Anwar, not always possible render secondary as BC.. cost a lot extra render time.

[vladimir.nedev]

Actually, the adaptive dome light and adaptive lights don't work at all when the light cache is disabled.

I don't think what Boyan suggests is a good solution, it's better to disable just the adaptive dome light, no need to disable light cache as well.

Most likely, it's some edge case with surfaces visible to some rays but invisible to others. The adaptive lights don't like this.

If you can send a scene, we can try to fix it.

Greetings,
Vladimir Nedev

[Robert]

yeah I can send the scene, which is working now with 'EIS adaptiv' set to off.

[boyan]

Hey, Robert

Could you please reduce the GI - BF subdivs to a defaulted value of 8(now this is set up to 16), It Is not recommended to change it at all.

Cheers,

[Robert]

Just to repeat what Boyan wrote: The bug seems to be gone after remove all V-Ray packages in the V-Ray Add/Remove package menu (last point in the list) .. menu. Not sure why, but till now it seems to work.

[vladimir.nedev]

Just to repeat what Boyan wrote: The bug seems to be gone after remove all V-Ray packages in the V-Ray Add/Remove package menu (last point in the list) .. menu. Not sure why, but till now it seems to work.

When you remove all V-Ray packages, one of the packages removed is the one on the Render item with the V-Ray render settings.
So you are resetting the Environment Importance Sampling to NOT use Adaptive dome light.
That could be the reason.

Greetings,
Vladimir Nedev

[Robert]

Yeah, its basically not really helpful. To me it has to do with scene scale and adaptiv. But I have problems with EIS also in shadow catcher (mate). So I hope to isolate that bug in the future.

[boyan]

Hey,

Robert, when you reset the scene settings you can bring back the L/C settings and change the Progressive to Adaptive mode, Enable the Adaptive and compare the result. I will send scene file and video with both renders and comparison of them, as you can see the issue in Diffuse Render output is gone.

Cheers,

[Robert]

Yeah seen that. I will keep testing that. So each time I run into that I will go through the steps. Maybe that way we find the true reason.