Change number of buckets

[Sbrusse]

Hi,

I'm rendering in bucket mode, I love that mode, maybe because I'm using render engins for 15 years but also because I can see the final image once the bucket is done.
That being said, on my 4090, I do not use 100% of the GPU the same way I do when I do Gaussian Splat or other render engines.
Would it be possible to increase the number of buckets to try and squeeze those last 5-15%.



I have 6 buckets currently, but maybe increasing at 8 would help pushing it more.
Is there a maxscript that would activate this ?

Thanks
Stan

[vladimir_krastev]

Hi, thanks for posting. In the V-Ray GPU FAQ it says that

Due to GPU utilization during the rendering process, Bucket size cannot be changed and is automatically determined for your frame. However, the Bucket size is not dynamic (the size of the buckets do not change during rendering).

Here is the article about it.
It is better if you use progressive mode for V-Ray GPU. Please use it if the reason not to is just an old habit or emotional attachment towards bucket. If there is something else please share with examples.
Please check your GPU utilisation using the V-Ray Benchmark. It should be 100% during rendering.

[Sbrusse]

I understand for the size of the bucket, my concern was about the number of buckets, not it's size.
I'll check on a few frames if it works any better in final renders using progressive.
It's not only an old habit, like I said, I can see the final quality straight away for each of the buckets, which for me is often better than using the progressive renderer.
Progressive renderer is great for IPR, but for final, I still rather see the buckets. I can track my mouse, and I can see straight away the areas that will cause issues. Instead of seeing an issue and then hope that when it hits the treshold, the issue is gone.
For final quality assesment (noise, glossy elemets, materials that dont render correctly, etc) buckets is still a win for me. Hence why I would like to be able to fine tune the settings just to try to squeeze the last % out.
If not possible, I might do the final steps using buckets and then switch for progressive right before rendering, hopeing that it will stay exactly the same, will it?

Thanks
Stan

[Muhammed_Hamed]

Hi Sbrusse

I understand that you prefer using buckets, it is up to you
You can change the number of buckets as well as the bucket size with those environment variables(try at your own risk)
Increasing the number of buckets will consume more GPU memory, which is expected to happen. We made a decision to hide these controls as the default values work better in all cases

NUM_BUCKETS_PER_GPU

VRAY_GPU_BUCKET_SIZE

First one is number of buckets per GPU, default is 5
second one is bucket size, default is 256

Best,
Muhammed

[Sbrusse]

Woop woop!

Awesome, thanks!
I tried the progressive, and it was actually worse in gpu usage than the default buckets.
Indeed using slightly more ram but winning those few % as well
Now that I'm able to tweak this, it's much better!
Thanks

[Muhammed_Hamed]

What settings did you use with buckets? did you increase the number of buckets?

[Sbrusse]

Yes, simply changed the bucket amount to 10 instead of the 6 I had as default, and much better now.
By the way, GPU utilisation is faaaaaaaaaaar better than if I use progressive.
So I'll stick with bucket for now