There has long been a persistent and out-of-the-blue problem periodically had by a few users of DAZ Studio, that appears to stump forum helpers every time. It’s often wrongly assumed to be a graphics drivers problem. That can be true if the user recently upgraded to a new version of DAZ Studio that requires new card drivers for CPU rendering, but does not apply if no such change was made.
Symptoms: The user has not recently upgraded DAZ Studio to the latest version. An unspecified “Error during rendering” has caused iRay to fail, with that rather unhelpful message. If the user tries to close rendering and render again, they are told that iRay is already in use (even though it has definitely closed). Other render modes are still possible.
Solution: A little digging with my handy new Technical Search Engine suggests that the only one who got it right was one ‘JaeAlexisLee’ in 2015, who painstakingly went through every damn thing that could be wrong with the wayward scene. At last it was found…
“Found it! Occurs if the Render SubD level is higher than 1!”
Where to find these settings: I’ve tested this solution, and it does indeed cure the problem instantly and perfectly. So, here are where you find the settings you need to change in DAZ Studio 4.12…
Manually putting the above settings back to Base | 0 | 0 and saving the scene then enabled an iRay render to run again fine. I then switched them up to High Resolution | 1 | 1 for better resolution, saved the scene again, and once again DAZ Studio rendered fine in iRay. The “Catmark” setting appears to be harmless.
HD morphs presets as probable cause: I suspect these settings were silently changed on loading one or more HD Morph presets from the Library, and that such things need high settings in order to accommodate the morph dial’s need for lots of polygons in the Genesis figure mesh. Possibly those with amazingly powerful graphics cards can handle such HD things, so it may indeed be a RAM problem ‘of a kind’. But many DAZ Studio user will not be able to run their figure at that high level. Ongoing nuke-from-orbit solution: just shun all HD figures on the DAZ Store, at least until you get an $800 graphics card.