Fireflies happening more often

[jstrob]

Hi Normand, can you try to check Sub-pixel mapping and clamp output to 5 or 8 in the color mapping section. I thknk it comes from your hdr env reflection.

[Normandthegang]

Thanks, we will try that and will let you know how it goes!
BTW we're using a vraysun/vraysky so I guess it could come from the vraysky.

[GALACTUS]

I have the same issue too in a road tunnel with no sun or sky. We have tried min/max samples at 1/24, 4,24 with clr threshold values at .01,.003 and .001 with no positive result other than at 1/24 0.0001 the render times hit 6hrs/frame.also noticed random black dots on my Z pass too which moved about the frame at random. Rendered using VRay3.6.03. Also using Deadline which i do not think is the issue. We are testing on back burner tonight on 3.6.04... fingers crossed.

[GALACTUS]

Just ran the output through the denoiser and also tried min and max settings at 1/100 0.01 with no joy too.

[Normandthegang]

Hey guys, quick update:

We turned off the specular contribution of as many lights as possible, and cranked the the max subdivs up to 100. This for the most part fixed the issue in the sense that the random hot pixels are sampled enough to prevent getting blown out, but the sample rate pass shows that the underlying issue is still definitely there. Subpixel mapping and clamped output didn't seem to affect things much.

While the adjustments generally worked, the render times went through the roof while buckets hung on the trouble spots. With an animation of a few thousand frames, this can't be the permanent fix. Thoughts?

[Normandthegang]

Hi everyone,
Is there an update on the subject? we're still having that issue on other project...
Thanks!

[DeadLift315]

We are getting similar issues as well. The only reliable solution has been to enable sub pixel mapping, unfortunately this changes the look of an animation significantly. Max ray intensity does not seem to prevent the fireflies or even reduce their occurrence.

Here is an example of the problem we had recently. https://youtu.be/sNUGHwAnoy0

Any developer feedback would be greatly appreciated!!!

Thank you!

[matanov]

We are getting similar issues as well. The only reliable solution has been to enable sub pixel mapping, unfortunately this changes the look of an animation significantly. Max ray intensity does not seem to prevent the fireflies or even reduce their occurrence.

Here is an example of the problem we had recently. https://youtu.be/sNUGHwAnoy0

Any developer feedback would be greatly appreciated!!!

Thank you!

Have you tried making the VRaySun invisible?

[DeadLift315]

Thank you for the fast response!

We use HDRI images to light our scenes and we have attempted making a separate v-ray dome light for reflections with reduced intensity. This does fix the fireflies but also makes the reflections in the image look incorrect. I suppose we could make a specific dome light that only effects offending objects. Theses are usually metals with high gloss values. The problem with this is we would have to at least render a low quality version of the entire animation to identify the offenders and then fix them on a case by case basis. A more global solution like max ray intensity functioning as well as it was shown in the tutorial videos would be much more desirable.

[matanov]

You can send me the problematic parts of the scene to check them out here.

[baumgore]

Has this been solved? Geting a lot more fireflies since VRay 4.0. "Max Ray intensity" which helped in the past seams to be broken now. Could you please chech it's working? Can't see any differences in my renders as I change it to extremes. E.g. from 20 to 1. Fireflies persist.