HDRI changes intensity based on rotation

[snivlem]

Hi,

With V-Ray (any version) it seems that HDRI's will change intensity even though there is a slight difference in rotation. This happens with most scenes and is most visible with V-Ray RT.

Here's a scene lit by one HDRI domelight. Both renders were run for the same amount of time.

Top one has a rotation of 235. The bottom has a rotation of 236 using PG's HDRI.





You can see a drastic difference in illumination.

Is this a V-Ray bug? RT did not sample it properly or a user setting where I have to turn something on? Thought it was subpixel mapping but this makes no difference.

Edit: The bug seems to be fixed when changing resolution to 1024 from 512. So it's not really a bug but the default setting was not high enough to sample the HDRI properly - maybe this default setting needs to be updated???

[tashko.zashev]

Hi,

There is a drastic lighting difference between these renders. Would it be possible to send a simplified scene to test it here? Perhaps we also need the HDRI file because the one I used for the tests here worked fine even with 512 texture resolution.

[snivlem]

I can do this, is there still an FTP I can upload to? This scene will be using a paid asset so I can't upload here or post a link. Thanks.

[tashko.zashev]

I can do this, is there still an FTP I can upload to? This scene will be using a paid asset so I can't upload here or post a link. Thanks.

Yes, we can provide login details, just send us an email to support@chaosgroup.com with link to this thread.
Thank you.

[snivlem]

Thanks, I've uploaded the scene (See Ticket #170532 for details)