[Richard]

JD sorry mate I found a weird little one that was causing me to think either I had stuffed my workflow or there was a bug in studio. Turns out to be (at least this end a bug born by SU camera's imported to Studio).

The issue pops up when saving out physical sky as HDRI and slotting back in as IBL channels.

Here is what I did, should be easily reproducable:

1. Open SU file export sang / physical sky with default camera to render,
2. Open MXS file with Studio - test with Fire "Perfect"
3. Now save sky as HDRI slot back in as IBL - test again "Way over bright"
4. Create camera in Studio / physical sky - test with Fire "Perfect"
5. Now save sky as HDRI slot back in as IBL - test again "Perfect"!

All tested with the Tom clear sky preset in Studio to limit the issue to the camera - indeed shows an issue that sky saved with SU camera imports (and clones of) save out overbright (too intense) HDRI!

To note the SU camera operates correctly on both HDRI & Physical sky saved out from Studio created camera.

[JDHill]

Check your step 4; I would guess that your two cameras have different EVs.

What I see here is that EV=15 is the point where the HDR will match when replacing the Physical Sky it was created from. If, however, you move your camera's EV to 17, then the HDR look darker than the Physical Sky did, and vice versa -- if you change EV to 13, the HDR will look brighter. In your example, you are comparing HDR outputs from cameras with EV=14 and EV=15; the HDR from the EV=14 camera is brighter than the HDR created using the EV=15 camera you created in step 4.

So the moral of the story would be: when creating HDRs in Studio, use a camera where EV=15. I have no idea whether this would be a bug, or if it's just how things work.

[Richard]

Thanks JD! IMHO that seems like a workaround for a bug? Y/N - not a bug maybe but at least incorrect functionality. I would imagine the sky generated would be as the set sky irrespective of the camera settings - the camera simply used for sun orientation as relative!

Though good thing is it isn't a "Plug Bug!"

[JDHill]

I have given very little thought to why it might work how it does, so I can't really comment on whether or not there would be a bug here. I can really only say that, according to my observations, this is how it does work.