Several Issues with V-Ray 6 in 3ds Max 2024

[ryan_kelton]

Hi all.
I'm having some issues with V-Ray 6 in Max 2024.
So issue 1 is that render times seem to be slower in 2024 compared to 2022. The exact same scene runs in 27.6 seconds in 2022 but 50.6 seconds in 2024.
The next issue is that GPU rendering hangs on "Starting GPU engine..." causing Max to completely lockup. The length of time that it locks up seems to be proportional to the complexity of the scene. For the project mentioned above, it locks up for well over a minute, but a smaller scene might only lock up for 15 - 20 seconds.
Lastly, once a render has finished (both GPU and CPU renders), Max again locks up. This too is proportional to the scene complexity. Initially I thought this might be the denoiser, but disabling it made no difference.

So far I've tried complete reinstalls of 3ds Max and V-Ray, complete reinstalls of the Nvidia drivers (I tried both the studio and gaming drivers, using DDU to uninstall). Disabling my anti-virus did not help either.
Kind of lost about where to go from here.
Both versions of Max are running V-Ray 6 Update 1.2 6.10.08.

My GPU is an Asus TUF RTX 4090 and CPU is a Ryzen 9 3950X with 64 GB of system RAM.

Thank you.

[^Lele^]

Hi all.
I'm having some issues with V-Ray 6 in Max 2024.
So issue 1 is that render times seem to be slower in 2024 compared to 2022. The exact same scene runs in 27.6 seconds in 2022 but 50.6 seconds in 2024.

Difficult to fathom without a scene.

The next issue is that GPU rendering hangs on "Starting GPU engine..." causing Max to completely lockup. The length of time that it locks up seems to be proportional to the complexity of the scene. For the project mentioned above, it locks up for well over a minute, but a smaller scene might only lock up for 15 - 20 seconds.

Like the above.

Lastly, once a render has finished (both GPU and CPU renders), Max again locks up. This too is proportional to the scene complexity. Initially I thought this might be the denoiser, but disabling it made no difference.

The unloading from RAM of stuff like proxies, and tiled textures, isn't instant, but can currently take a rather long time.
The task manager will show max using one core and the RAM slowly unloading.

[ryan_kelton]

Hi.
So regarding the first issue, here is a screen capture of the same scene rendering in Max 2022 and 2024.

2022:
https://youtu.be/1ZZM8-eWb6s
2024
https://youtu.be/kri4YH4zaeM

And here is a different scene rendering on GPU where it locks up on "Starting GPU engine..."

2022:
https://youtu.be/L4dzVL9n7Hw
2024:
https://youtu.be/cvWcuuXoNac

And regarding the last point, I understand that. It's just that it seems to take significantly longer in 2024 than in 2022 to complete that process.

[^Lele^]

Eheh, no i meant a physical scene.
There may well be reasons on our side for the apparent slowdown, but without a copy of the scene to check, it's impossible to tell.
If the issue reproduces with us, then it's half-way to a resolution.

Open a ticket to support, and mention this thread. (V-Ray help menu in Max.)
They should be able to guide you through the submission process.

[ryan_kelton]

Ah, ok. Thank you. I'd be glad to provide them with whatever they might need. I'm a software developer in my day job, so I know how frustrating it can be to try to figure out these seemingly one-off user issues, especially when integrating into a platform you don't control.

Thanks again.

[^Lele^]

Yep: particularly for GPU, drivers can have a great impact.
Plus there may have been modifications to various sub-systems that may lead to longer rendertimes by default, but one may be able to get back the performance altering some parameter or the other, or at the least have an idea as to that is actually going on.

[^Lele^]

Thanks Ryan,

our excellent support shared the scene with me.
I'll poke you as we'll have a clue.

[^Lele^]

Regarding the delay on load, and after each render stop/end with either engine:
It was hit and miss to repro, but Yavor finally nailed it down to the substance plugin regenerating texture previews (with profiling, so we know for sure.).
Which makes sense with how the CPU graph looked like after the render had stopped (for up to 25 seconds on the specific machine...):


Interestingly, as i don't have the substance plugin installed on my max 2024, the scene for me was blazing fast.

We're still investigating the GPU reports.

[ryan_kelton]

Ah, thank you! I hadn't considered that Substance might be the culprit. I will open a support ticket with them and share your findings once the GPU issue is investigated, since that could also be an issue with Substance.

[^Lele^]

I haven't been able to reproduce the issues you have with GPU, on the installation without substance.
I'd suggest you see if the issue disappears as the substance one does.

[ryan_kelton]

Yep, you were correct. The issue does seem to be related to Substance. Removing the plugin worked, but also removing all the substance2 maps from the scene (with the plugin still installed) also worked. And like you said, blazing fast.

I'll open a support ticket with Adobe and/or Autodesk, since this doesn't seem to be a V-Ray issue. I'll make sure to update this thread with whatever findings they come back with.

Thank you guys for the help, I genuinely appreciate it.

[^Lele^]

Thank you for being so gracious about it all.