VraySampleRate strange rectangular areas

[Dimiter.Enev]

Hi there,

I'm not sure that this is a problem as it doesn't have noticeable effect on the final render, but I had never seen such effect before and wanted to ask if this is normal.
I'm getting these unusual rectangular areas with different shades in the VraySampleRate layer. They seem to not align with the buckets, so it's not related to bucket size.
Here take a look:


This is the rendered image (just resized):

The material of the background plane is just diffuse color without reflections or any other maps.

I'm just rendering another test with different dark grey background material and on it I have the same rectangles with even more apparent difference in color, but again no visible effect on the final render.


P.S. If I remove the lamp, and render only the background, the rectangles disappear. Same effect if I do the opposite. So it looks like this is connected with the big difference in the complexity of the background and the lamp.

[Zdravko.Keremidchiev]

Would it be possible to send us the scene to support@chaosgroup.com or attach it here?

[Dimiter.Enev]

Hi Zdravko,

I had sent the scene on the e-mail.
Things that may (or not) be related:
I'm using 1950X + Asrock Taichi X399 + 4x8GB G.Skill 3200 C16 on Win 10 Pro 64bit. V-Ray 3.60.03

Some additional info:
The rectangles disappear or change intensity when render region is used on parts of the image and are most apparent when rendering the full image.

[vlado]

Thanks for the scene, but this is normal and is not a bug (unless it also leads to artifacts in the image itself, but the image seems fine in your case). V-Ray may decide to sample lights and/or other effects differently in different parts of the scene due to the adaptive lights which could lead to different sample rates in those areas. The final RGB image should be fine though.

Best regards,
Vlado

[Dimiter.Enev]

Thanks for the reply Vlado. I had started to think that this may be some kind of hardware problem as I had never seen such effect on my Intel system over the years.

[vlado]

Thanks for the reply Vlado. I had started to think that this may be some kind of hardware problem as I had never seen such effect on my Intel system over the years.

It's a recent thing (since the adaptive lights were introduced). So long as the final RGB image is fine, it should be ok.

Best regards,
Vlado

[Dimiter.Enev]

I understand. Thanks!
И весело посрещане на новата година!