Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: redlad on 2015-05-20, 11:26:46

Title: Lighting Artifact
Post by: redlad on 2015-05-20, 11:26:46

Hi,

I am getting some weird artifacting on some object in my file. I have to crop my image to show just the issue, for copyright reasons.

Does anyone have any idea how to address this? It's just that I don't have much time to troubleshoot it. You can see it right across the center of this attached file along the shadow terminator.

Thank you

Title: Re: Lighting Artifact
Post by: Ondra on 2015-05-20, 11:28:57

Hi,
is there any bump/normal map? Does it go way if you use meshsmooth (or increase its subdivisions)?

Title: Re: Lighting Artifact
Post by: redlad on 2015-05-20, 11:48:04

Hi Ondra,

No bump or normal map, it's a basic shader. I will try the Meshsmooth like you mention and get back in a few mins

Thanks

Title: Re: Lighting Artifact
Post by: redlad on 2015-05-20, 12:24:14

Hi I have tried the Meshsmooth approach hand I get the same thing. No luck.

I do have a light above this object and have adjusted the 'directionality' on the light to 0.55. Surely this wouldn't make this artifact happen?

When I do a material override of a basic grey shader, I get the same issue.

Any help is greatly appreciated as I am on a very strict deadline with this one.

Title: Re: Lighting Artifact
Post by: Frood on 2015-05-20, 12:31:47

Are you allowed to attach that (and only that) specific part in a max scene so that we can have look at the mesh? If so please do...

Good Luck!

Title: Re: Lighting Artifact
Post by: maru on 2015-05-20, 13:05:25

This looks like the terminator line issue ( https://coronarenderer.freshdesk.com/support/solutions/articles/5000516180 ) - solution would be to subdivide the mesh multiple times. It would be great if you could create a similar scene where this happens.

Title: Re: Lighting Artifact
Post by: redlad on 2015-05-20, 14:58:10

Quote from: maru on 2015-05-20, 13:05:25

This looks like the terminator line issue ( https://coronarenderer.freshdesk.com/support/solutions/articles/5000516180 ) - solution would be to subdivide the mesh multiple times. It would be great if you could create a similar scene where this happens.

Thank you Maru! 3 Turbosmooth Iterations seems to have done the trick.

You saved the day, thanks a mill!

Title: Re: Lighting Artifact
Post by: jorari71 on 2015-06-08, 07:24:46

Have you tried to apply an "autosmooth" with 45º from:
Select your object->ConvertTo->Poly-->modify tab->select this faces you want to smooth->and select "autosmooth" with the option of 45º for instance.

The trick is that you don't have to increase your number of triangles and of course, the structure of your mesh, because maybe you wouldn't like to and maybe it should be "untouchable" for some reasons.

:)

Title: Re: Lighting Artifact
Post by: maru on 2015-06-08, 11:24:29

Quote from: jorari71 on 2015-06-08, 07:24:46

Have you tried to apply an "autosmooth" with 45º from:

This will not work.

Title: Re: Lighting Artifact
Post by: jorari71 on 2015-06-09, 09:25:31

Why maru?

Title: Re: Lighting Artifact
Post by: romullus on 2015-06-09, 09:28:35

Because example in OP post is shadow terminator not a smoothing problem.

Title: Re: Lighting Artifact
Post by: maru on 2015-06-09, 11:06:50

Quote from: jorari71 on 2015-06-09, 09:25:31

Why maru?

Look at the example with teapot in this article: https://coronarenderer.freshdesk.com/support/solutions/articles/5000516180
It is smoothed, probably 30deg or so, but even if you would turn it up to 180deg, the issue would still be there. Corona does not work like scanline.