IES Lights faulty - following export the insert

[Ibear888]

Hello,
I exported (with origin) several hundred IES lights to a file. Then I "inserted" (with origin) and "embedded" sub-sets of those lights as "individual objects" into target files.

The IES lights work properly in the source file, which is where i created the IES lights. Source file, the rgb render results are same whether in CPU or GPU mode.

In the target file, the IES lights are defective. The results are very different in CPU versus GPU modes.


Any idea how to correct this? Is there a problem when exporting then importing IES lights?

Thanks, Jeff

ps. Shadow, resolution, and other settings do not seem to correct this issue.

[Peter.Chaushev]

Hello, Jeff,

Apologies for the late reply!
If you haven't already contacted support@chaosgroup.com directly, could you please send over the project for investigation?
They may require some additional info to be able to track down the cause of the illustrated discrepancy. This includes:
- the full version numbers of Rhino and V-Ray for Rhino
- confirmation whether restoring the default render settings fixes the issue
- confirmation whether the issue is reproducible only with particular .ies files or with a specific project file

Submitting the scene (or a part of it) for inspection via a file-sharing service of your choice would also be appreciated.

Kind regards,
Peter

[Ibear888]

The problem appears related to a combination of the light cache and moving back and forth between final and interactive and CPU/GPU. Restoring to default fixes the issue temporarily.

[Peter.Chaushev]

The problem is identified in the V-Ray core. Its ticket has just had its priority raised.
We are currently debating on a possible temporary workaround for V-Ray Next for SketchUp & Rhino. Will post an update as soon as possible.
Thank you for all the info you have provided in this thread!

Kind regards,
Peter

[Peter.Chaushev]

A fix is currently being devised. It will be available in an upcoming update.
In the meantime, you can overcome this sharp light cut-off by disabling the Camera Auto-exposure, lowering the EV value and then re-enabling the Auto-exposure toggle.
Please let us know if you stumble upon any further issues!

Kind regards,
Peter