Blender Versions
I was wondering if it's just my setup, or whether Blender 4 (4.0.2 to be precise) was incredibly unstable for anyone else. It crashes regularly, usually when switching the viewport shading to rendered, (Cycles). I have a 4080 16GB, 3900X and 128GB of system RAM. My scenes aren't particularly complex.
From 4.0.2 I can go forwards (4.2.0) or backwards (3.6.0). Backwards works OK. That still crashes from time to time but much less often. Forwards I'm not too sure about Diffeo compatibility, or even if it's worth the bother with respect to stability. I mostly use Animation Layers and Diffeo.
There's also a rendering issue isn't there, meaning version 4 I have to use "fixed" Blender builds to prevent colour bleeding thart someone has kindly provided at Diffeo's bitbucket thread.
Comments
I switched out my renderer in preferences (Edit -> Preferences -> System) from OptiX to CUDA and it seems much more stable now. I don't think Cycles OptiX codepath is right in the head.
Spoke too soon. Still crashes regularly.
Blender 4.2 works quite stable in my case. It only crashes from time to time.
4070, 64 GB system RAM, but I don't use Viewport shading to rendered.
Still in the process of updating to the newest Diffeo version, which comes as Blender Extension. Probably scheduled for the weekend.
I was going to do that today Singular but I read there's an issue in general with 4, specifically colour bleeding, e.g. limbs give you a blueish ring around them. Someone on Diffeo's Bitbucket is posting up Blender builds that fix this problem in Cycles.
Diffeomorphic is fully compatible with blender 3.6 and 4.2, then 2.9 is also supported but not all features will work due to limits in 2.9.
In my experience Blender itself is generally unstable, you need to get a LTS release for something decent enough for production, that's also what LTS is for anyway.
Yup. 4.2 was a total fail. CUDA error. Couldn't render at all. I extirpated my drivers with DDU and reinstalled them. Didn't help. I've reverted to 3.6 and posted a bug about it, though I'm kind-of sceptical it's an actual bug and not something wrong with my system (Cycles is the only thing that doesn't work though - Daz 4.22 is fine with the 552.22 Studio Drivers).
Blender got update to 4.2.1.
Thanks for the information
The actual 4.2 is marked as LTS
4.2.1 is out since August 20th, marked as 4.2 LTS.. Does it work with the latest Diffeomorphic version?
Yes.
Thanks for the fast reply. Very helpful!
I have a sneaking feeling my problems with Blender were to do with the NVIDIA Nsight installation that I used for dev work last year and never removed. Removing it solved the issue. Posting here so I no longer scare the horses with my problem!
(For those interested, I made a build of Blender's 4.3 alpha to debug the problem and posted a ticket about it here).