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Strange noise as black pixels with normal mapping.

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Strange noise as black pixels with normal mapping.

Post Fri Oct 13, 2017 3:03 pm

Hello everyone.

First of all, I'm sorry if this is a duplicated topic. The search didn't find any relevant similar post.

I have a bit of a problem with my materials. If I use normal mapping, even if just very little, I get a lot of black (unlit?) pixels on the shadow side of the mesh. I already tried using 512 samples in my lamp, and increasing the AA samples, but the difference is almost unnoticeable.

Here is the Yafaray rendered image:

Image

If you look at it you can see it looks grainy and just not right (although on the faces where the light hits it looks very good) and if you inspect closely you will notice that those are pure black pixels.

Here's a BI render to compare (Yafaray render is also rendered with direct lighting integrator):

Image

Comparing side by side, Blender's render seem to have some sort of blur applied on it, but I can't find a way to get smooth results like that with Yafaray. Antialias passes won't fix it.

Any tip or help is much appreciated. Thanks in advance. :)
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RREDesigns
 
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Re: Strange noise as black pixels with normal mapping.

Post Fri Oct 13, 2017 6:39 pm

Hello,

Please try texture interpolation setting to EWA instead of bilinear. Not sure if it will solve that problem but worth a try.
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David Bluecame
 
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Re: Strange noise as black pixels with normal mapping.

Post Sat Oct 14, 2017 12:48 am

Perhaps the Bump value for the normal map is too high?

If you can, upload a file that shows the issue.
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stoneage
 
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Re: Strange noise as black pixels with normal mapping.

Post Sat Oct 14, 2017 9:00 pm

Hi, and thanks for a quick reply.

Here you can see YR rendered preview and how it looks. Also, I don't see EWA interpolation option. Images are .png files if that matters.

Image

I could provide a blend file, but this is just the default material (Shiny Diffuse, if I'm not wrong), with no tweaks, just color and normal textures (for normal the "use as normal map" option is checked).

I could also provide the textures if you want to try, just let me know. Although it's not the first time I see this issue, so I guess textures are clean.
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RREDesigns
 
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Re: Strange noise as black pixels with normal mapping.

Post Sun Oct 15, 2017 3:13 am

Hello,

What yafaray version are you using? Please try using the latest version v3.3.0 which has EWA interpolation.
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David Bluecame
 
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Re: Strange noise as black pixels with normal mapping.

Post Sun Oct 15, 2017 5:05 pm

I was using v3.1.1. I downloaded the latest a couple of weeks ago but didn't install it apparently. xD

Ok, so I think EWA does help, but I can still get some pure black pixels, even on the faces that aim directly to the lamp, which is weird.

At this point I'm starting to think that maybe my normal maps are too noisy. When I make my normal maps I do it with sharp details, so I guess that might be the problem too.

Here's a cap with the latest YR version: [EDIT: The image is wide and not showing fully, use "right click -> view image" to see it]

Image
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RREDesigns
 
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Re: Strange noise as black pixels with normal mapping.

Post Sun Oct 15, 2017 6:26 pm

Hello,

Please will you upload a sample .blend scene with the texture(s) you are having problems with?

Thanks!
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David Bluecame
 
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Re: Strange noise as black pixels with normal mapping.

Post Sun Oct 15, 2017 11:36 pm

Sure, I can do that. I prepared 3 different materials, and they all have artifacts. While preparing the scene I noticed that rounded shapes are the ones that show more of this issue.

I tried pathtracing with the same result, but SPPM renders fine.

The file: https://drive.google.com/file/d/0B0tFflUWxeKrRlZacHdjcnVSTTg/view?usp=sharing
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RREDesigns
 
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Re: Strange noise as black pixels with normal mapping.

Post Fri Nov 10, 2017 5:54 pm

Hello everyone.

Is there any updates on this topic? :mrgreen:
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RREDesigns
 
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Re: Strange noise as black pixels with normal mapping.

Post Sat Nov 11, 2017 12:42 pm

Hello.

I don't know what it's going on with Drive. I always share stuff with it and it never asks for permission. I have reuploaded the file to Mega for easier download, [url=
https://mega.nz/#!nxh3nAJb!vkLHr-TPHzXs ... tRwatxXKsU
]here's[/url] the file.
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RREDesigns
 
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