VRay crashes when rendering model w/ grass (fur)

[mandy_lam]

Tried interactive on/off and different VRay/SU combo but no luck:
VRay next on SU 2020 - SU keeps crashing. Need to force close SU to recover
VRay 5 on SU 2020 - after 5+ minutes of rendering VR message window shows: "[RTOpenCL_impl::validate] 1: Abort was requested. Cancelling GPU rendering!". I've attached the message log in link
VRay 5 on SU 2021 - same as VR5 on SU 2020.
Originally I thought it was the laubwerk plants and trees in my model. But issue persists after deleting all laubwerk components. I then retrieved an older file before applying fur geometry and it works. So I believe the problem is the fur geometry.
thanks.

[konstantin_chaos]

Hi mandy_lam,

You might be running out of GPU memory.
Can you please share a stripped down version of your scene for testing?

Konstantin

[mandy_lam]

thanks for the prompt response!
I observe GPU memory usage during render and don't see it went above 15%. Please see this screenshot:

[mandy_lam]

Today I create a model with simple contour and grass materials. Render and found same failure. The symptoms varies across multiple runs. First time SU simply crashes, I reboot my PC and re-render, this time VR aborts w/o finish rendering. CPU usages is extremely high in all instances.
Please find below additional files recording today's test in same shared folder:
20201204 Simple Contour w Grass.skp - a simplified model for your testing
20201204 Sys Performance.jpg - task manager performance log showing resource usage while rendering
20201204 VR Settings.jpg - screenshot of my VR settings (CUDA, Interactive, NVIDA denoiser, etc)
20201204 VR Progress log.txt - VR Progress window log
I am on windows 10, all display drivers are up to date.
Please let me know if you need further info.
thanks.

[Peter.Chaushev]

Hello, mandy_lam ,
As Konstantin suggested, the issue is caused by extremely high memory consumption. The V-Ray Fur generates too much geometry on render time.
Please enable the Fur's option 'Level of detail' and set its 'Start Distance' and 'Rate' values to 100 (or even less). This should resolve your problem and speed up the export time of your scene while retaining its overall appearance.

Kind regards,
Peter

[mandy_lam]

it works. thank you!
May I ask: when I set start distance to, say, 50, what unit is used? Does it follow the length unit of my model info, in my case inches?

[glennco]

thanks Peter, I was having the same problem with Vray 5 & Rhino 7.
setting level of detail solved the issue.
Glenn

[Peter.Chaushev]

Glad to hear it!

The 'Level of Detail' parameters in V-Ray for SketchUp are always calculated in inches regardless of the display units of your project.

Regards,
Peter