Dark edges on metal

Use this forum for general user support and related questions.
Forum rules
Please upload a testscene that allows developers to reproduce the problem, and attach some images.
Post Reply
Rivental
Posts: 4
Joined: Mon Aug 16, 2021 4:33 pm

Dark edges on metal

Post by Rivental »

Hello, I have a problem with the metal in luxcore.
How can I get rid of these dark edges?
I had the same problem in Cycles, but when I switched to multiscatter ggx in principled bsdf, the problem just gone.
I don't see the multiscatter ggx option in luxcore.
Attachments
Luxcore
Luxcore
Cycles GGX
Cycles GGX
Cycles Multiscatter GGX
Cycles Multiscatter GGX
Last edited by Rivental on Sun Sep 05, 2021 9:19 am, edited 1 time in total.
User avatar
Dade
Developer
Developer
Posts: 5672
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: Dark edges in metal

Post by Dade »

The looks like a normal related problem (may a split normals is required). Can you post a test scene ?
Support LuxCoreRender project with salts and bounties
Rivental
Posts: 4
Joined: Mon Aug 16, 2021 4:33 pm

Re: Dark edges in metal

Post by Rivental »

Yes, maybe this is problem with normals. But i don't understand why multiscatter ggx solves this problem.
https://drive.google.com/file/d/1MFND83 ... sp=sharing
User avatar
Dade
Developer
Developer
Posts: 5672
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: Dark edges in metal

Post by Dade »

Rivental wrote: Wed Sep 01, 2021 7:25 pm Yes, maybe this is problem with normals. But i don't understand why multiscatter ggx solves this problem.
https://drive.google.com/file/d/1MFND83 ... sp=sharing
The problem is in how your NURBS are exported to Lux. This is a part of the mesh exported:

nurbs.jpg

As you can see, there are a lot of problems:

- very low triangles count;
- faceted;
- normals flipped (they point inside the object).

My suggestion is to transform the NURBS in triangle mesh inside Blender, so you have full control of what is going on and than render (i.e. export the scene) with LuxCore.
Support LuxCoreRender project with salts and bounties
Post Reply