I’ve been seeing this a couple of times, and this time I remembered to save the file. Sometimes - for reasons still unknown - Cycles decides to render what seems to be the welded mesh cage of a sub-d, rather than the actaul render mesh - see the attached screen grabs.
It seems to be file specific, and goes away if I copy/paste or import the file into a clean file. And as mentioned, I’m still not quite sure what I’ve done to make it happen, but it IS something that “happens”, meaning that the file is all good in the begining, and then goes awry.
I was hoping, that maybe the 3DM file could be of use to find out what’s happening and will of course report it, if I find out what I do “wrong”.
cycles bug.3dm (5.6 MB)