Just thoughts on troubleshooting steps
- If you load the old scene, it still calculates fine? (in case it is an update to Corona or some other plugin, and not a scene change, that has caused the issue)
- What happens if you use the 4K cache instead of the UHD?
- You can force a minidump, which if you want to send in a ticket will basically let us see what the software was doing at the time,https://support.chaos.com/hc/en-us/articles/4649117083409-How-to-report-issues-3ds-Max for forcing a crash
- I know you did some object hiding, but what about hiding everything leaving the HDRI and a new cube, does it work then? Then add objects back in groups?
- What happens with a Material Override set to a default Physical Material? Might pin it down to some translucency or volume textures.
- Thinking of volume textures, anything that uses a volume (including the absorption etc in a standard Phys Mat) is applied only to enclosed objects, and not to single sided things like planes? (Remembering that on a plane, Corona has no idea where the volume stops, which can "embed" the camera inside a volume)
The material override was a great idea that I hadn't thought of.
That narrowed it down to a material issue. I disabled the override and disabled displacement it got to rendering fairly quickly so i thought theres clearly a rogue material somewhere.
Couldnt find anything odd so went back to randomly hiding things.
I thought i found the problem object. When i hide the object the scene renders and the success rate increases significantly.
But when i apply a new blank material to the object the problem doesnt go away. Also the object in question renders fine when isolated.
The object in question or its material hasnt been altered for a dozen or so versions of this file either.
I then tried hiding half the scene but kept the problem object visible and the scene renders fine.
Im wondering if this is some sort of memory issue. I have 128gb in my system and using about half of it.
Since this scene was successfully rendered i have updated to 12.1 from 12.0
Ill do some further digging but i will try and send a minidump as this is looking like a very hard issue to troubleshoot without seeing internal workings.