Author Topic: Black Spots  (Read 4089 times)

2018-04-07, 18:44:01

menano

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I have been having some issues that no matter what I do I can't seem to fix.

After installing Beta 2's first build I started working on a scene, and everything was working fine, no crashes, very stable.

After a while I started to get some issues, the main being black spots (nan) in some areas of my image. (See attachment 1 + 2)
I am now 99% sure that SSS is the reason for this, as turning it off seems to fix it (Attachment 3) but as you can see, turning it off significantly changes the look I am going for.
After this bug appeared, another issue came and now when I try to turn on Bloom & Glare a big portion of my image gets covered in black (Attachment 4)

I have tried uninstalling and reinstalling Corona, going back to Beta 1, uninstalling and reinstalling C4D, but nothing seems to work.

I have been a huge fan of Corona since the first day I tried it, the software, the team, the community, but it seems I finally found a hurdle that is keeping me from using it and it upsets me because of all the pleasure I've had so far with it.
I hope this issue can be solved promptly and I can go back to enjoying this amazing engine


Scene created and tested in Cinema 4D R18 + R19 on Mac OS 10.11.6

2018-04-07, 20:27:42
Reply #1

Eddoron

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Didn't we have the exact same thread not long ago? What happened with that?

2018-04-07, 20:58:00
Reply #2

menano

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I posted this issue on the daily build thread, but to no avail

I uploaded my scene and Beng took a look at it but found nothing

I was just hoping this issue wouldn't die because I'm stuck and can't move forward, I've tried everything I can think of

2018-04-07, 21:24:38
Reply #3

romullus

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I'm moving this to bug reporting board. Please don't forget to upload your scene here: https://corona-renderer.com/upload and specify uploaded filename in this topic.
I'm not Corona Team member. Everything i say, is my personal opinion only.
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2018-04-07, 22:00:29
Reply #4

Beanzvision

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I'm moving this to bug reporting board. Please don't forget to upload your scene here: https://corona-renderer.com/upload and specify uploaded filename in this topic.
Thanks for moving it, scene has been uploaded, but unfortunately renders fine on my machine.

2018-04-07, 22:32:29
Reply #5

romullus

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Sorry, it was so quiet in the forum, that i dared to venture into C4D badlands :]
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2018-04-08, 00:26:07
Reply #6

Beanzvision

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No worries at all, I know what you mean. ;)

2018-04-08, 01:48:20
Reply #7

menano

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Apparently this used to be an issue in the 3ds Max version, what caused it and what fixed it then?

2018-04-08, 09:25:14
Reply #8

Beanzvision

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From what I've read there seems to be a variety of possible things that may cause them. Such as, a bad hdri, bumpmap/normal map, high gamma levels, SSS, bad uv's...resulting in rays striking an object/surface and not knowing how to deal with it hence producing a NAN (not a number). If it's material/setting related you could try doing a clay render using .mtl override with the default corona material to see if the problem persists. If it does, double check mat settings / test render etc. Process of illumination I guess. Although they happen in most renderers, it seems to be in rare cases. So with all that said, this is just my 2 cents worth. Hopefully someone will step in that has dealt with them before and provide you a solution!

2018-04-08, 18:36:28
Reply #9

menano

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As I mentioned I am pretty sure that the issue is coming from the SSS in the plants, as you can see the NANs are gone when I turn it off

Hopefully this can make it easier to solve the problem somehow, I have used SSS several times and never had issues, I really didn't want to have to turn it off

2018-04-09, 09:36:30
Reply #10

houska

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NaNs are, simply put, problems in the calculation. They can happen when something weird goes wrong or when something happens that we didn't expect when writing the shading code of Corona.

It's weird that menano can reliably reproduce it, yet beanzvision has trouble getting the black spots to appear. I suppose you both have the same versions of C4D and Corona. Another thing that comes to my mind is that the uploaded scene might be missing some assets? I'd namely check the SSS channel, which seems to be the culprit...

2018-04-09, 15:26:53
Reply #11

Beanzvision

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NaNs are, simply put, problems in the calculation. They can happen when something weird goes wrong or when something happens that we didn't expect when writing the shading code of Corona.

It's weird that menano can reliably reproduce it, yet beanzvision has trouble getting the black spots to appear. I suppose you both have the same versions of C4D and Corona. Another thing that comes to my mind is that the uploaded scene might be missing some assets? I'd namely check the SSS channel, which seems to be the culprit...
Agreed, originally the initial upload didn't contain texture maps to which I requested another full upload with everything intact. Even so, I had re-assign textures after the second upload but still couldn't produce said NAN's even with already pre set settings in place.

2018-04-09, 16:32:20
Reply #12

menano

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Yeah, when I uploaded it by the second time, I uploaded all textures and all materials were exactly as in my scene. I'm sure beanzvision can confirm the SSS was on for the plants

2018-04-26, 07:17:58
Reply #13

Beanzvision

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Is this any different with the latest build?

2018-04-27, 17:01:34
Reply #14

menano

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I have not tested it, but in the meantime the issue seems to have disappeared