CAD Data Normal Problem

[Hesekiel2517]

Hey there,

i have a lot of shading errors with my current cad project. I tried to edit the normals, but it always looked the same in Octane. I tried to use the Modo Rendercache and Voila: Errors resolved. Genereally i don't like to use the rendercache since it's not reliable. Is there a way to fix this?

I'm using the current Modo (12.0 and 12.1) and Octane Verisons (3.08.2.133)
edit: This Trick only works with 12.0. In 12.1 the error stays

Rendering with Rendercache ON

Rendering with Rendercache OFF

Thanks in advance

[face_off]

Are you sure this is not a Kernel->Ray Epsilon issue? And have you rendered out the Normals passes to get a better idea of what is going wrong? Are you able to send me a scene which exhibits this issue pls?

Thanks

Paul

[Hesekiel2517]

Hey Paul,

sorry for the delay. Here is a scene for you and also a few renders. You can see that the normals are different. Something is going wrong with the smoothing, i think.

This works only in 12.0 and it doesn't matter which version of Octane is used (as far as i know). Render Cache off produces errors, render cache on does not.

Thank you for looking into this!

[face_off]

sorry for the delay. Here is a scene for you and also a few renders. You can see that the normals are different. Something is going wrong with the smoothing, i think.

This works only in 12.0 and it doesn't matter which version of Octane is used (as far as i know). Render Cache off produces errors, render cache on does not.

Thank you for looking into this!

I think the problem is the UV's on the mesh. If you view the UV render pass you can see the problem.

Paul

[Hesekiel2517]

Hey Paul,

thanks for looking into this. This solved the problem (both making new UVs and simply deleting them). Are the UVs effecting the normals? Since it's CAD Data the UVs are totally unusable. So Material uses only Linear Projection. Furthermore this Problem also shows up with no textures at all. Also why does it work if the rendercache is used? I'm glad that this helped, but i really don't understand why

[face_off]

Are the UVs effecting the normals? Since it's CAD Data the UVs are totally unusable. So Material uses only Linear Projection. Furthermore this Problem also shows up with no textures at all. Also why does it work if the rendercache is used? I'm glad that this helped, but i really don't understand why

I sent the scene to OTOY for comment. I will let you know when I get a response.

Paul

[Hesekiel2517]

Thank you!

[Hesekiel2517]

Hey Paul,

did you get a response? Had this issue today again and searched for the problem one hour until i remembered that UV Map thing

Thank you in advance

[face_off]

Hey Paul,

did you get a response? Had this issue today again and searched for the problem one hour until i remembered that UV Map thing

Thank you in advance

I cannot find their response but I recall it was something like, yes, the UV map is effecting the normals in this case, you you need to fix the UV map.

Paul