I'm noticing that I get some weird faceting when i use the SSS + detailed displacement, or normal maps sometimes.

as an example here's voronoi noise used to drive displacement. I see this faceting with either normals or displacement.

no idea how to get rid of this with karma, it seems to be an issue with both cpu and xpu. have tried all sorts of combinations of things. am i missing something or does this need a fix? its more clearly visible when the SSS scale is lower.

Should there be a hip file attached?

meant to attach this image but here's a hip file simplified, you can clearly see the faceting artifacts on the characters hands. if you play with the displacement/normals/SSS radius youc can see it more or less clearly all over the model.




https://drive.google.com/file/d/1o0XC73JQehmChjwEQCaLY-fJXaCcp_5F/view?usp=sharing [drive.google.com]

ChristopherRutledge
meant to attach this image but here's a hip file simplified, you can clearly see the faceting artifacts on the characters hands. if you play with the displacement/normals/SSS radius youc can see it more or less clearly all over the model.

Looks like subdivision wasn't enabled.

jsmack

ChristopherRutledge
meant to attach this image but here's a hip file simplified, you can clearly see the faceting artifacts on the characters hands. if you play with the displacement/normals/SSS radius youc can see it more or less clearly all over the model.

Looks like subdivision wasn't enabled.

ah, that would explain it, where am i missing the subdivision setting? ive been looking for it in karma. i thought that it was "dicing" and it worked differently from subdiv in other renderers like redshift or arnold?

ChristopherRutledge

jsmack

ChristopherRutledge
meant to attach this image but here's a hip file simplified, you can clearly see the faceting artifacts on the characters hands. if you play with the displacement/normals/SSS radius youc can see it more or less clearly all over the model.

Looks like subdivision wasn't enabled.

ah, that would explain it, where am i missing the subdivision setting? ive been looking for it in karma. i thought that it was "dicing" and it worked differently from subdiv in other renderers like redshift or arnold?

Look for subdivision scheme in the scene graph details for the mesh prims, it should say 'catmull clark' or something like that and not 'None'. As for how to set it, it's a USD property, so there are several ways. It can be set for you automatically when importing from object level when using scene import. SOP import has a subdivision checkbox on it somewhere. You can also right-click the property in the details pane and create a node to edit the property on that prim.

wow! thank you! great to know.

It would be great to have Subdivision properties accessible from the Render Geometry Settings LOP. Seems like the logical place to have it (and I swear it used to be in there too, although I might be crazy).

Hamilton Meathouse
It would be great to have Subdivision properties accessible from the Render Geometry Settings LOP. Seems like the logical place to have it (and I swear it used to be in there too, although I might be crazy).

It would be nice, but I think due to it being a mesh attribute and not a primvar, it must be set on the mesh, and not anywhere hierarchically like render settings can.

Maybe their is, or could be a 'karma:force_subdivision' kind of thing?