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White Specks in Render

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aswaab
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Hi,

I am getting white specks in my render with PBR. I am not talking about noise - I can see the image is noisy. I am talking about all the pure white specks that are all over the image. I have tried adjusting every setting I can think of, but I still get the specks. Anyone know what the problem might be?

HIP file is too large to upload here, but here are my settings…

-2 Area lights with raytraced shadows (16 area samples each)
-PBR renderer
-Pixel Samples 3X3
-Min Ray Samples 20
-Max Ray Samples 40
-Diffuse Limit 3
-Raytracing Bias 0.01

Attachments:
bedroom_01.jpg (246.1 KB)

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wolfwood
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A ‘hacky’ approach is to add the Color Limit property to the Mantra ROP and set its value from 1000 to something like 5. It limits the intensity of a sample which can help get rid of speckles. (Which are generally caused by secondary glossy bounces.)
if(coffees<2,round(float),float)
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aswaab
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This is being caused by using an area light set to “physically correct.” The white spots are reflection bounces. Haven't really figured out a way to get rid of them unless I change the light setting or set reflection bounces to 0.

I would prefer not to clamp my values if possible.

Any other ideas?
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edward
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Stupid question, but are you lighting by looking at the images with say a 2.2 gamma? By default, PBR will output linear images.
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aswaab
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Yes, I am looking at the render with 2.2 gamma.

I'll post a simple hip file that shows the problem in a little bit.
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aswaab
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Some more pics + hip files.

Please, if someone can take a quick look, maybe you know what the problem is.

Thanks!

Attachments:
teapot_half_distance.jpg (167.3 KB)
teapot_physically_correct.jpg (233.5 KB)
gi_test_physically_correct.hipnc (500.4 KB)

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aswaab
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Half-distance file in this post.

Attachments:
gi_test_half_distance.hipnc (500.4 KB)

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mzigaib
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Did anyone got to get rid of the white specs? Any tips on this?

aswaab
The white spots are reflection bounces. Haven't really figured out a way to get rid of them unless I change the light setting or set reflection bounces to 0.

I would prefer not to clamp my values if possible.

Any other ideas?

The reflection bounces you mean diffuse limit?

Thanks.
https://vimeo.com/user2163076 [vimeo.com]
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Asche915
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Same Question :idea:
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tamte
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that post is 5 years old

do you have fresh scene where you see white specs?
that problem was usually resolved by changing the noise level/max samples and decreasing Color Limit

if you are using former 5 year old scene, try replacing mantra node with new one, and maybe materials as well
Tomas Slancik
FX Supervisor
Method Studios, NY
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