Another texture problem? Squares, etc, on skin

HorusRa

I don't think I've run into this before and I'm stumped. 2 screen shots one of the side of the head and one of a hand, in both you can see squares etc. They are Iray renders. Any ideas?

Please forgive the fireflies. I let this render only long enough to get a decent view of the artifacts. A full completed render does not solve the problem.

mjc1016

Two quick questions...are you using a geoshell?

Is there a displacement map?

That's definitely NOT the shadow problem...

HorusRa

mjc1016 said:

Two quick questions...are you using a geoshell?

Is there a displacement map?

That's definitely NOT the shadow problem...

Hey mj,
Ha, I'm not real familiar with geo shells and I'm guessing, almost certainly I'm not using a geo shell.
No Displacement map per se', however there is a Bump, turning it down/off makes no difference as far as the artifacts are concerned.
After posting I did a fast conversion of the scene/figure to 3Delight and test rendered and those artifacts were not there, but of course (as murphy's law would apply), I wouldn't bother with this scene in 3Delight, as it just wouldn't be able to be pulled off as well, and even more so because of the volumetric lighting effect.

HorusRa

update: Getting rid of any hdri in use caused the artifacts to go away completely. Also Glossy Reflectivity and Glossy Roughness reduced to 0 while using an hdri nearly got rid of the artifacts, but not completely.

mjc1016

Ok...yes, it's an interaction among the various parts of the scene...namely the HDRi and volumetric effects. 

The reason I asked about geoshells is some things like the DA Snow product and some tattoo items do use them.

I've baked some normal and displacement maps, that have that slightly faceted look (in Blender if the settings aren't just right), that's why I asked about those.  It doesn't really show up unless you look closely at the map or under certain lighting conditions.

This doesn't happen to be Nosferatu, by any chance?

If it is then it could be the specular maps (for Iray they may be used in the glossy channel somwhere)...they should be a black and white/greyscale images, but some of them are actually RGB images with an embedded color profile (the arms, face and torso maps...the others legs and anatomical elements don't have the embedded profile).

barbult

I had a similar problem in DS 4.8.0.59. When I tried it in 4.9.0.54 Beta, the problem disappeared. If you have the beta installed, you might want to try that and see if it is fixed.

HorusRa

barbult said:

I had a similar problem in DS 4.8.0.59. When I tried it in 4.9.0.54 Beta, the problem disappeared. If you have the beta installed, you might want to try that and see if it is fixed.

I don't have the beta installed. I was actually going to download the beta this time (I didnt for 4.8) but the description was saying something that when installing it, it does something to your data-base, etc, etc. and I didn't want it messing anything up, so I figured I'd just wait for the official release.

HorusRa

mjc1016 said:

Ok...yes, it's an interaction among the various parts of the scene...namely the HDRi and volumetric effects. 

The reason I asked about geoshells is some things like the DA Snow product and some tattoo items do use them.

I've baked some normal and displacement maps, that have that slightly faceted look (in Blender if the settings aren't just right), that's why I asked about those.  It doesn't really show up unless you look closely at the map or under certain lighting conditions.

This doesn't happen to be Nosferatu, by any chance?

If it is then it could be the specular maps (for Iray they may be used in the glossy channel somwhere)...they should be a black and white/greyscale images, but some of them are actually RGB images with an embedded color profile (the arms, face and torso maps...the others legs and anatomical elements don't have the embedded profile).

Yes, it is Nosferatu, the RDNA version, not the daz version. The daz version, the day it was released, reminded me that I had Nos from rdna in my wishlist, so I bought both the day daz's was released, but I found rdna's to be more scary/monstrous, so I wanted to do a scene or two with him right away.
Well I checked on the glossy channel thing and he is using a glossy map (err, or Specular map) in the glossy color channel. The color was black and it had the map, which like you said looked kind of gray/black & white, or thereabouts. I got rid of it and turned the color to white (?) (only because Sikleyield in her iray tutorial says verbatim: "you never want to use a color Glossy with human skin, not in Iray"), and it helped a lot, but again, didnt get rid of it completely. I then got rid of the glossy parameters that I spoke of before, and that helped too, I guess, none got rid of it completely, but it's very close now, while using an hdri. Getting rid of the hdri, like I said gets rid of it completely, but I have to have an hdri. What hdri, no matter who made them doesn't seem to be an issue, as in it doesn't seem to be a "quality" of the hdri issue. I'm not so sure the volumetrics are having anything to do with it, though it might be, I haven't tested that. I mean I had a few test renders before atmocam was used, but don't remember if it was there or not. I also got this during the christmas holidays on a house/snow scene, where these artifacts were in the snow, in a couple areas, however, in that case the artifacts were more like circular shapes and looked silverish/metallic, just like the current ones. However, during a full completed render they eventually disipated and were gone upon completion. I'm starting to notice these artifact types in iray, sometimes they are subtle, but upon close inspection one can see them. They are not always there, but sometimes.