Strange Transparent Skin Problem

mikethe3dguy

I have a frequently-used G8F character I have saved in a couple scene subsets (different clothing) that have always rendered just fine. Recently she renders with somewhat transparent skin, but transparent in a strange way: shadows she casts are also transparent, and any solid objects behind her skin in the render do not show through her skin, that is: her skin causes transparency in the rendered image, not in the scene, if that makes sense. The attached image should explain it. This effect started appearing around the same time I upgraded from DS 4.16 to 4.20 so it might be related to that but I'm not sure. I have scrutinized her skin shaders and can't find anything problematic.I have other G8 characters saved as scene subsets with the same skin shader, but they render fine.

 

Spacious

You might try reseting your render settings for that scene to default, and then changing whatever settings you want to get render quality where you want it.  Or you could open up a scene that's rendering correctly and make notes about the render settings to compare them and fix whichever one is wrong.  I experienced this issue once and while I'm not sure which setting it was that caused this, I'm pretty sure that's how I fixed it.  Otherwise to just fix that render, you could just duplicate the layer several times in Photoshop or GIMP and the layers will eventually add up enough to no longer be transparent. 

mikethe3dguy

Spacious said:

You might try reseting your render settings for that scene to default, and then changing whatever settings you want to get render quality where you want it.  Or you could open up a scene that's rendering correctly and make notes about the render settings to compare them and fix whichever one is wrong.  I experienced this issue once and while I'm not sure which setting it was that caused this, I'm pretty sure that's how I fixed it.  Otherwise to just fix that render, you could just duplicate the layer several times in Photoshop or GIMP and the layers will eventually add up enough to no longer be transparent. 

Well I've opened up completely new scenes, adding a regular G8F and my character from one (or both) of her scene subsets, then rendered the two characters together in the new scene and compared. New G8F: fine / Existing G8F from scene subset: transparent skin. Doesn't seem to be render settings.

mikethe3dguy

Spacious said:

Otherwise to just fix that render, you could just duplicate the layer several times in Photoshop or GIMP and the layers will eventually add up enough to no longer be transparent. 

That might be a decent temporary fix, but I'm going to be doing dozens of renders with this character over the next months, so I need to figure out the cause.

Spacious

Are you rendering using canvases?  There's some options in there that could cause this.

mikethe3dguy

Spacious said:

Are you rendering using canvases?  There's some options in there that could cause this.

No, not yet. Not sure I understand it even - looks like a lot of extra work when you're trying to get out many renders per day.

Spacious

Opening up a new scene doesn't necissarily reset all render settings, many of them carry over from scene to scene.  There are some items, especially from some other sites that do strange things to render settings.  Again I'm not sure what could be causing this problem, but I'm fairly certain that there are no surface settings that can cause a surface to make other items and even shadows transparent like that.

There is a completely new version of Iray itself included in the new 4.20 version of DAZ and if you've got an older GPU driver it could definitely cause some strangeness.  Apparently it's not a good time to download drivers from NVIDIA, something about a hack, but if you've got the file from the last one you installed sitting in a download folder it's worth a try.  Windows has a tendency to overwrite parts of the GPU driver files as part of OS updates.

mikethe3dguy

Spacious said:

Opening up a new scene doesn't necissarily reset all render settings, many of them carry over from scene to scene.  There are some items, especially from some other sites that do strange things to render settings.  Again I'm not sure what could be causing this problem, but I'm fairly certain that there are no surface settings that can cause a surface to make other items and even shadows transparent like that.

There is a completely new version of Iray itself included in the new 4.20 version of DAZ and if you've got an older GPU driver it could definitely cause some strangeness.  Apparently it's not a good time to download drivers from NVIDIA, something about a hack, but if you've got the file from the last one you installed sitting in a download folder it's worth a try.  Windows has a tendency to overwrite parts of the GPU driver files as part of OS updates.

I'm running an RTX 2080Ti with the latest NVIDIA Studio drivers (upgrade necessary to render with 4.20). It is not render settings - I reset all the render settings to default and the problem persists.

MelanieL

This sounds very much like something reported in the Beta thread back in November. A few people reported getting the problem, but Daz techies were having problems trying to reproduce it. I don't know whether it was supposed to have been fixed by now (the thread is many pages long and I didn't read them all - most are about other matters). There was some reference to using Mono instead of Chromatic SSS (? I have no idea what that even means !?)

Here's a link: https://www.daz3d.com/forums/discussion/comment/7145751/#Comment_7145751

Paintbox

This is a bit of a long shot, but try and see if the render is close to the 0,0 location in your world. Shadow problems often come from renders away from the center.

mikethe3dguy

MelanieL said:

This sounds very much like something reported in the Beta thread back in November. A few people reported getting the problem, but Daz techies were having problems trying to reproduce it. I don't know whether it was supposed to have been fixed by now (the thread is many pages long and I didn't read them all - most are about other matters). There was some reference to using Mono instead of Chromatic SSS (? I have no idea what that even means !?)

Here's a link: https://www.daz3d.com/forums/discussion/comment/7145751/#Comment_7145751

Thank you! Going through the thread now.

mikethe3dguy

Paintbox said:

This is a bit of a long shot, but try and see if the render is close to the 0,0 location in your world. Shadow problems often come from renders away from the center.

Yeah I've been through the grinder with problems caused by that myself, mostly the dreaded black forehead lines. So much so that in this set of renders I readjusted the whole environment (which is a multi-block neighborhood) so the characters would always be very close to world center. Not to mention the test renders I've done once the problem appeared by just dropping a G8 into a new scene, so they're at 0,0,0.

M-C

I've encountered such issues with spectral rendering activated. 
It doesn't happen every time but in some scenes this seems to be the culprit in my case. 
Unfortunately I'm still looking for a solution as well. 

mikethe3dguy

M-C said:

I've encountered such issues with spectral rendering activated. 
It doesn't happen every time but in some scenes this seems to be the culprit in my case. 
Unfortunately I'm still looking for a solution as well. 

Thanks, but I'm not using spectral. Good luck solving your issue.