Daz rendering "wrong"

chrisskyles

I'm trying to figure out a number of issues I've been having lately. Two in particular have really bugged me, and I can not figure out what is causing them.A note: All images were rendered with https://www.daz3d.com/render-queue-3 . I normally let that run overnight. 

The first one can be seen in the first 2 images on the field. Looking at them individually it's difficult to see any difference, but viewing them side by side, you'll notice the floor is in a very slightly different position in the two.

The problem with that is, nothing changed between rendering the two images - and trust me, I checked. My first thought was obviously I messed up and somehow moved something in the scene causing the floor to be in a different position. After going in and checking it though, I could not find a single thing that was moved or out of place, so instead of changing anything, I just re-rendered the entire image on a whim. To my surprise, the 2nd attempt the floor was in the "correct" position, despite nothing in the scene changing between renders. (When I opened it to look for changes, I never saved it either). 

 

The second issue comes from the 3rd image here: 

 

I can't post the "error" image here, but I can certainly explain it. Take a loot at the guy in the middle in the black shirt - behind him in the background is a girl in a sweater. After rendering this image initially (No noticable errors), I went back and wanted to make a few small changes, and edit them into the original image via spotrender. The spotrender area was the top half of that guy in the middle, which included the girl in the background.

When preforming the spotrender, something odd happened - the guy was nude, as was the girl in the background, her hair was gone, and the lighting was different. (Thus the reason I can't post the error image - both characters are fully nude in it). I closed the spotrender (I was spotrendering to new window), attempted it a 2nd time, and the 2nd time around it worked perfectly. 

 

So my question is - what is going on here? Why is daz rendering images "wrong", but then on a re-render attempt it's working perfectly fine. (Side note - I've noticed similar errors a few other times, but these two examples are the most stark ones imo. As subtle as the first one is, some are even moreso). 

 

Products used (Just environments - too many to bother listing all the clothing/character/hair used) - 

first two, the main background is https://www.daz3d.com/american-football-field

along with a freebie from renderosity - athletic grounds by richardandtracy. The ground that "moves" is actually a plane, which has the entire shader from "grass" copied to it. (I believe it was the grass from the athletic grounds freebie, though it could have been from the football field my memory escapes me at the moment. I may open it up later to check). 

The 2nd, the main area is from https://www.daz3d.com/office-cafeteria . The background (everything outside the windows - so mostly the area that appears red and black) is not part of the image, it was added afterwards. The actual image was rendered with a transparent background - so everything behind the windows in the original is transparent.

Everything (except the spotrender) was rendered with render queue 3. 

GPU is an MSI 4090 suprim liquid X, studio drivers 531.41 - everything rendered on daz 4.21.0.5 

Hopefully I provided enough information - I'm really struggling to figure out what's going on here. 

 

richardandtracy

There is a little bit of a problem with the athletic ground freebie, and I don't know if it's having an impact on your image, it may be. iRay uses single precision numbers, and sometimes it runs out of digits for the precision. As a result in the distance the distance between the lines and the tartan disappears, needing the morph to lift the lines to see them. Due to the size of the ground, this may also be happening over the whole scene, and if the clothing is too close to the character's skin, they could both be rounding to the same value, with the order of rendering on the final image being a matter of chance. A way to cure it could be to hide the character bones inside the clothing, so only the clothes render. Regards, Richard.