Using HDR Light Studio with Octane Plugin 2026.x does not work

[davidvonbehr]

Hi team,

when using HDR Light Studio with any of the 2026.x plugins the temp HDRI does not refresh automatically anymore.
Platform: Mac OS X 26.5 on M4 Max

When using Cycles it works just fine and also the recent Blender/Octane Plug-in versions were OK.

Could you please fix this?

Best,
David

[linograndiotoy]

HDR Light Studio is an external commercial application, and its Blender/renderer integration is not developed or maintained by OTOY.

From what you describe, the issue seems to be related to how HDR Light Studio updates the temporary HDRI and sends/refreshes it in Blender. For that reason, this should probably be reported to the HDR Light Studio developers as well.

If the same workflow worked with older Octane for Blender versions and stopped working with the 2026.x plugin, it would be useful to know the exact HDR Light Studio version you are using and what update/refresh mechanism it relies on.

Thanks!

[davidvonbehr]

Thanks a lot for your reply!

It is just the latest release of HDRLS + Blender Plugin. It worked fine with Blender 4.5 LTS and Octane 2025 and does not work with Blender 5.0 and Octane 2026 anymore.

I guess that it is a simple issue, because the link between HDRLS and Blender is just a temporary generated HDRI file which is updated every time you paint a light. This automatic refresh of the HDRI seems to be broken or deactivated, so you have to reload the HDRI every time which is very inconvenient. Cycles does automatically refresh the HDRI, so I guess that HDRLS is working fine.

[linograndiotoy]

The question is: does it work in 5.1/Cycles?

[davidvonbehr]

The question is: does it work in 5.1/Cycles?

No, it does not

The developer of HDRLS told me that they currently do not support Blender 5.1 - just up to Blender 5.0, because there is an issue with Blender 5.1 on Mac OS, which hasn't been resolved yet.