Problems with high res gpu renders in Modo

[rusty_sena]

Hi all,

I'm new to Vray so please bear with me. I have a new PC with a Threadripper (32 cores), and 2(ea) Nvidia 3080 gpus. 64 gigs of Ram for the computer. I'm using Modo 14.2.2. So far I'm loving Vray with the gpu preview render. It's everything I hoped it would be. I've been doing product renders of around 4k x 3k pixels with no issues. These products are pretty simple and don't have a lot of complexity or materials. Now I'm having to put these products into environments (think ArchViz). I'm building these environments from scratch - they look like archviz scenes with lots of geometry and high res materials. When I try to render these scenes at the 4k res, Vray is quitting or crashing every time. I've tried using the render inside the Modo workspace as well as the standalone renderer. Neither works. I watch the log (?) as the data flies by and have noticed that it seems to be a memory issue. I should note that I can do renders at lower resolutions so it seems likely it's a memory issue but I can't be sure because I don't know all the tricks and tips with this software. I've done countless searches on how to fix this issue as these renders are my business and while the previews are nice, I was hoping to get the same quality but at a higher resolution while still using the gpu's. I know this is a rather vague explanation so I'm willing to send a full package of my Modo scene but it's rather large because of the image maps. I'm wondering if I'm asking too much of the gpu renderer and maybe my expectations were too high. I'm used to using a Mac with no real gpu power so I thought Vray plus modern gpu's would solve my problem. Anyhow, can you help with some tips and tricks to get high res renders using the gpu? I will send any info you might need but I don't know where to look or what to send so you can help me diagnose.

Thank you in advance,
Rusty

[boyan]

Hey, Rusty,

Happy new year!

Thank you for the post. Could please try the following set-up: A/ Enable the hybrid rendering GPU + CPU, you can find the option in the V-Ray Preference tab and should check-in CPU and GPU. B/ When rendering High Res images use bucket mode aka Adaptive and save image as EXR Tiled 16/32.

Please let me know if you have any other questions and I will answer you.

Cheers

[rusty_sena]

Hi Boyan, thank you for your response. After reading a lot and trying a few things I found a possible culprit: Displacement maps. I have been importing a few Quixel scans and using their maps. In my shader tree the materials are created automatically with Quixel bridge. As I went through all the materials I was using, I noticed the included displacement maps on maybe 7 materials. I thought I'd try deleting them and now the image renders at the resolution I need it to. I've tried just about every other setting I could find after reading a lot of posts about optimizing memory usage for the GPU's. Btw - I had tried all of the things you mentioned in your suggestions and none of those seemed to work except to just use the CPU as the GPU processor. That will render but kinda defeats the purpose of using the GPU in my opinion. At some point I even tried using ChaosCloud and it also rendered but took about 30 minutes. Once I turned my displacement maps off, it rendered in about 11 minutes using my machine.

Best,
Rusty