Environment Map slot clamps HDRI sky?

[atrask@hksinc.com]

Hi,

I'm wanting to render my sky out in a separate pass to tweak in comp.

I have an HDR sky bitmap wrapped in a VrayHDRI shader in the Environment Map slot.

When I save out the sky pass as a 32 bit .exr, it behaves like an 8 bit image. Bringing down the exposure in Photoshop turns it to grey mud. There's not a huge exposure range I get from adjusting the HDR sky bitmap exposure in Photoshop.

I've tried turning off color mapping and gamma, turning off exposure control.

It feels like the environment slot clamps down the HDR data from the HDR bitmap.

Can anyone shed some light on this?

Thanks in advance!
Andrew

[vlado]

If you right-click on an overbright area of the VFB to bring up the pixel color information dialog, do you get HDR values there?

Best regards,
Vlado

[atrask@hksinc.com]

Hi Vlado,

An overbright area of the sun in the VFB brings up a 6.483 float value. I save that out as a 32 bit .exr with no compression. Bringing down the exposure tool in photoshop turns it to mud.

I have a screenshot of the HDR image used in the environment slot with the exposure brought down in Photoshop for comparison.




*Edit

I set the color mapping to 'Linear multiply', gamma 1.0, all multipliers at 1.0 to amp up the float. The float in the VFB was 7808.000 on a hotspot. Saved out 32bit exr it's still 'clamped' when I try to bring down the exposure.

[atrask@hksinc.com]

Ok guys false alarm. I reset the Vray render settings and it's behaving fine now. I had gotten this scene from a co-worker. Not sure what the issue was though. Nothing was set on 'clamp' that I could tell.