All scene assets disappear from VFB and scene crashes

[carlwilliamsvisualisation]

Hi, I wonder if someone can help me understand why this is happening.

It tends to be on 'heavier' scenes, but randomly my scenes will crash during interactive rendering when making really small changes. Prior to the crash, everything in the VFB will instantly disappear, and then lock me out of stopping the interactive running and saving.
It tends to be really sporadic and doesn't really seem to follow a pattern or happen when I am editing certain objects/materials. I have a feeling it may be something to do with scattering large amounts of grass objects in a Forest Pack but I don't seem to be to replicate the issue with any consistency. It catches me by surprise when making the smallest change to a material for example.

Any ideas welcome and thanks!

Carl

[romullus]

Gathering minidump after the crash would be the first step towards identifying cause of the issue i think.

[maru]

Which version of Corona are you using? If you are using Forest Pack, please also make sure that you use the newest available version.
Other than that, I can echo what Romullus said: capture a minidump and send it to us
Here is how - https://support.chaos.com/hc/en-us/articles/4649117083409-How-to-report-issues-3ds-Max
And here is the contact form - https://support.chaos.com/hc/en-us/requests/new

[carlwilliamsvisualisation]

Hello,

Thanks to you both for your responses. I have collected the minidump file here and packaged it up. Could you please assess and let me know what you suspect the issue is?

As I described before, all can be going fine for about 3-5 minutes of making changes whilst interactive rendering, then all of a sudden, everything apart from the HDRI disappears in the VFB, and I'm either able to stop IR if I'm 'very' quick, or it goes unresponsive and crashes within 5 seconds.

Many thanks,

Carl

[hurrycat]

Hello,

I came across this problem 2-3 times in the past, in different projects. All of the times I am almost certain it was because of Forest Pack.

The crash would occur randomly, even if you moved/rotated another object irrelevant to the Forest objects, sometimes after 1 minute, sometimes after 5 minutes.

I upgraded to the latest Forest Pack Pro 9 that had a bugfix regarding crashes in IR with large objects but didn't fix it (I didn't remake the Forest Objects though, in case they had corrupted settings from Forest Pack 8).

I enden up remaking all Forest objects, rebuilding the surfaces they were scattered on (collapsing their stack and any parametric modifier they had e.g. Conform).

I pinned it down to some specific Forest objects (lots of small rocks scattered on the terrain) that seemed to lead to a crash when they where visible but, due to the randomness of the issue I am not 100% sure they were the culprit. I deleted those and the problem was gone.

3ds Max 2025, Corona 11 (hotfix1)

[Aram Avetisyan]

Hello,

Thanks to you both for your responses. I have collected the minidump file here and packaged it up. Could you please assess and let me know what you suspect the issue is?

As I described before, all can be going fine for about 3-5 minutes of making changes whilst interactive rendering, then all of a sudden, everything apart from the HDRI disappears in the VFB, and I'm either able to stop IR if I'm 'very' quick, or it goes unresponsive and crashes within 5 seconds.

Many thanks,

Carl

This specific crash is in Embree, related to AVX.

It is best to get full PC specs and also the scene to do some troubleshooting.

[maru]

Sounds like this is the same issue as described here: https://forum.corona-renderer.com/index.php?topic=43296.msg233393#msg233393

@anyone with this issue - please contact us about it at https://support.chaos.com/hc/en-us/requests/new

Thank you!

[carlwilliamsvisualisation]

Hello,

Thanks to you both for your responses. I have collected the minidump file here and packaged it up. Could you please assess and let me know what you suspect the issue is?

As I described before, all can be going fine for about 3-5 minutes of making changes whilst interactive rendering, then all of a sudden, everything apart from the HDRI disappears in the VFB, and I'm either able to stop IR if I'm 'very' quick, or it goes unresponsive and crashes within 5 seconds.

Many thanks,

Carl

This specific crash is in Embree, related to AVX.

It is best to get full PC specs and also the scene to do some troubleshooting.

Hello,

I'm not too familiar with 'Embree' and 'AVX' haha, can you explain what that is in more basic computing lingo if possible lol.

PC Specs are as attached. I'm also running a GTX 4080.

The crash happened again this morning whilst in interactive rendering, I only tried to move a proxied tree in top view and it instantly crashed after removing all geometry from the VFB. This seems like a pretty major issue, given that the scene can be rendering fine and then randomly decides to crash at any given moment. I'm having to save every 5 minutes at this point to avoid losing work constantly, however I am losing a lot of time due to having to reopen the scenes constantly.

What's the best way for me to share the scene, there are a lot of animated vegetation proxies in the scene, the overall size of the file is quite large.
 

Many thanks,

Carl

[TomG]

Scenes are best shared by ticket, because a) any size can uploaded and b) you aren't then sharing it with everyone on the forum, just with the Corona team. https://support.chaos.com/requests/new .

In a slightly detailed but still kind of vague but hopefully understandable description, Embree can be thought of as low-level code (that is, very close to the CPU unlike regular compiled code) provided by Intel, and AVX is an instruction set on the CPU, also primarily developed by Intel, which are designed to accelerate certain functions, with Embree being for raytracing and AVX being for mathematical functions. We can call on them from our code to take advantage of that acceleration compared to code we write and compile ourselves. But of course we don't write or maintain either :)

PS neither is specific to Intel processors.

[maru]

As I have already asked, and Tom said, please send us any problematic scene (archived with all assets) here: https://support.chaos.com/hc/en-us/requests/new
We will try to reproduce it. If we succeed, we should be able to fix it, or at least understand what is going on.