Error : [GPU light cache] Could not allocate buffer

[andy_smith]

I've been working on a scene and render for the past few days and have rendered several times without issue. I have now added a domelight with HDRI and am getting an error saying: [13:56:06.812] Error : [GPU light cache] Could not allocate buffer of size 2059MB!

I have 64Gb of system ram and a RTX 3080Ti GPU. Which of my system specs is unable to provide2059Mb of buffer and how can I fix this? Nothing else is running on my PC so there should be no shortage of resources as far as I know.

I have tried setting the option to resize textures in the V-Ray GPU rollout to Resize to Texture Size 32 (the lowest resolution) but it gave the same error.
I have tried the On-demand Mip-Mapping option too - same result.
I have tried reducing the resolution of the render output to 500px (I was previously rendering this scene successfully at 2560px).
I have tried deleting all of the Cosmos models from the scene to just leave basic geometry.

None of these have cured the problem.

All that seems to work is switching off the HDRi but I don't see why I should need to do this in a relatively simple scene. Also, I use the same HDRi regularly and can do so now in a far more complex scene, without an issue. How can I troubleshoot this?

Thanks!
Andy


P.S. If I select RTX at the top of the Settings window in the asset editor and then click the three vertical dots next to the word RTX, I am able to see my GPU listed but unchecked. I can then check/tick the GPU. This will stay checked/ticked until I click CUDA or CPU and then click RTX again (at which point it is unchecked again). What does this mean/do to check/tick the GPU in the list?

[diana.milenova]

Hello, Andy,

Could not allocate buffer of size is usually a memory-related error. You were correct to try to optimize the project. There may be something else causing the issue, not necessarily the HDRI.
Can you please open a ticket by clicking here and share the project with the 3D Support team?
We will be happy to investigate and see what and why may be causing this behavior.

If this is alright, please use the Pack Project tool to avoid losing any assets (Extensions > V-Ray > Pack Project) to make an archived copy of the project, and upload it here.
Please make sure to include the exact V-Ray version in the ticket.


Regarding the second question:
The option to check a graphic card is there for users that may have multiple cards and would like to select which card/s to be used for the CUDA or RTX rendering.
The "clearing" of that selection after changing the render engine has been noticed by our developers and has been fixed in V-Ray 6.00.02.
Can you please check what is the current V-Ray version from Extensions> V-Ray > Help > About?
You can update V-Ray to version 6.00.02 from here.