Bucket artifact in DR

[flat]

DR the following scene (max2024) to see the bucket artefact.
https://drive.google.com/file/d/1sby...ew?usp=sharing

Both host and server are using V-Ray 6.20.03 (Same for Nightlies and Official 6.20.02) + 3dsMax 2024.2.1.

It looks like there is a problem with the GI.
Adaptive Light is disabled, Adaptivity clamp 100 etc. have no effect.

What is the cause?

[vladimir_krastev]

Hi, thanks for posting. The box is overlapping the wall and this is causing buckets.

It is a rule of thumb to avoid overlapping faces.
In this example it is very curious since it one slave is rendering one of the overlapping faces and the other slave is rendering the other.

[flat]

Ah, in the case of 2sided (translucent), the overlap of the side that cannot be seen from the camera also has an effect.
I learned a lot.

Thank you for investigating the cause.

[flat]

After further review of this issue with our customer, it appears that the issue is with the 3dsMax's OCIO (ACEScg) Color Management and V-Ray Light Temperature color settings in 3dsMax 2024.

Please try DR the attached simple scene. (Make sure to make another machine the DR Slave)


In my environment, the bucket artifact can be seen only once on the Slave machine for the first time DR Render. (Very strange)
screen capture
https://drive.google.com/file/d/1mFv...ew?usp=sharing

It seems that the bucket artifact can be seen every time in the customer's environment.

[vladimir_krastev]

Hi,

It seems that the bucket artifact can be seen every time in the customer's environment.

I couldn't reproduce this issue here with your second scene. Ofcource we used a separate slave machine that is on our local network. Ran it multiple times and no buckets.

it appears that the issue is with the 3dsMax's OCIO (ACEScg) Color Management and V-Ray Light Temperature color settings in 3dsMax 2024.

I can't reproduce this and stopping the ocio color management does not fix the buckets in your oak_sample.max scene (this was the first thing I tried back when I got your first scene).

To recap, your first scene does not cure with any other than fixing the overlapping faces. Your second scene does not reproduce any issues on our setup.

Are you using the latest versions of V-Ray? Check if you have any active environment variables related to ocio workflow and delete them.
For instance if you have such set up at one machine and not the other this can cause issues.

[flat]

that's strange. It reproduces 100% in my and my customer's environment.
There are no environment variables for ocio. I double checked.
Deleting the 3dsMax Preferences folder (2024 - 64bit) on Server and Slave also has no effect.

I got the DR temporary scene from the following folder on the Slave machine.
C:\Users\[Username]\AppData\Local\Autodesk\3dsMax\2024 - 64bit\ENU\temp

The temporary DR for the first time is 1st_vray_server_scene_20204.max.
The second time is 2nd_vray_server_scene_20204.max
(The scene is attached)

To compare, the first time the VFB Display Correction is OCIO (ACES), and the second time it is sRGB.
Why does the VFB Display Correction change between the first and second times?

[flat]

Is there anyone other than the Chaos person who can test this?
I don't know how to find the cause.

[flat]

Possibly the same cause was logged by Aleksandar.
https://forums.chaos.com/forum/phoen...56#post1208456

[vladimir_krastev]

Hi, it could be related. I tested your last uploaded scene again and it does not reproduce buckets with distributed rendering. Here it is:

[vladimir_krastev]

Hi again, I did a bit more testing with your scene.
The way you have sent it, it has no bitmap textures and does not reproduce buckets.
If we add a bitmap to the wall material it renders with buckets:

This is the same bug reported here.

If your client has buckets with the same exact scene that you've originally uploaded in post #6 then they may have some other issues.