pbr rendering artefact

[roughsporty]

I get this weired rendering artefact in the shadow area of the torus.

Can someone explain me, why that happen?

torus_pbr_test.hip

[3__]

Try changing the torus to polygon.

Also it renders much faster with a simpler shader (lighting model only).

-cpb

[symek]

You mean self shadowing? ( it's hard to see it due to gamma 1 of your image, but I guess this is it.) Like cpb already said, you should render it as a polygon subdivision surface (mesh won't subdivide in render), or change raytrace bias on Mantra ROP.

hth,

skk.

ps I noticed also Shading and Ray Quality are much too high. Values like 5 are mostly helpful in cases like noisy or detail textures/materials.

[roughsporty]

You mean self shadowing? ( it's hard to see it due to gamma 1 of your image, but I guess this is it.) Like cpb already said, you should render it as a polygon subdivision surface (mesh won't subdivide in render), or change raytrace bias on Mantra ROP.

hth,

skk.

ps I noticed also Shading and Ray Quality are much too high. Values like 5 are mostly helpful in cases like noisy or detail textures/materials.

Thank you both.

Polygon and subd do the trick. Shading and Ray quality where at 5 as I tested the scene. A value of 1 should be fine for the most time.