render artifact; black shadowy areas dependant on scale
sriesch
Posts: 4,241
In my current render, I'm seeing weird black shadowy chunks here and there. If you zoom in and render, they go away. (see screenshot with the same thing in the left and top right except for camera zoom change). They also seem to move around a bit on occasion, perhaps due to changes elsewhere in the scene.
How can I fix these? If it turns out to be render setting related, I've attached a screenshot of my render settings. However, I didn't notice this issue until this morning (but possible I just didn't notice), and there have been no recent render setting changes, and only one lighting change (a new pointlight which when turned off has no effect on this issue). The scene is lit with uberenvironment, one distant light, and one pointlight. UberEnvironment is just the default settings plus either "Set Quality 3Hi.dsa" or "Set Quality 4Xhi.dsa".
Daz 3D is part of 
Connect
DAZ Productions, Inc.
7533 S Center View Ct #4664
West Jordan, UT 84084
Licensing Agreement | Terms of Service | Privacy Policy | EULA
© 2025 Daz Productions Inc. All Rights Reserved.
Comments
Only thing I can see with the render settings is you Shading rate should be somewhere between .2 or .1 for best results. Are you using deep shadows on your lights? I'm not sure if its fixed or not in this new version but they were causing artifacts in renders.
Thanks for catching the shading rate, that was supposed to have been set to 0.1 when I installed DS, I must have missed that installation step. However, that did not fix it. All lights are set to "raytraced (software only)".
Correction: actually, it turns out that did fix it enough for me after all, at least at the moment. Thanks! The problem is no longer showing up in the final render, but I can still see it in one place in spot renders. Perhaps because it's still there but reduced to the point that it only happens in the small render viewport (which effectively is like zooming out as per original test).
Please show a wire shaded screen shoot, I suspect your mesh is a mess.
The final render works fine now with the above-suggested shading rate correction of 0.1 . I still saw the issue in the spot render only with that value, but if I set the shading rate to 0.01, then it goes away from there as well. Should I treat the shading rate as something that should be adjusted per scene to fit what I'm doing, or should I just permanently set it at the smallest value that fixes this issue as I find them?
However, in case you were curious, here is the wireframe. (The flat surface upon which the overlapping M and P letter objectss are placed that had the shadow is a single 4-sided polygon; you can't see the bottom line in the screenshot because it extends WAY down, and if I showed it all you wouldn't be able to see the trouble area.)
Sorry to say but yep it is a mess. There are more than likely a lot of overlapping faces and that will cause all sorts of weirdness.
So you are saying that the black spots are being caused not by the surface I see them on, but rather by the nearby surfaces? Also, I put the M and P objects in the same space, and both are also embedded in the large flat surface. I commonly have objects intersecting (often unavoidable, but in this case one could resize rather than embed; is that preferable, or is that not an issue?
You could raise one of the letters slightly to prevent the faces of the letters from occupying the same virtual location. The OpenGL preview will have the most problems with that while the 3DeLight render engine may or may not have a problem depending on the shader and shader setting used.