EXR not saving linear data????

V-Ray V-Ray for 3ds Max General
1

I’m having a problem where my linear renders saves as .exr files out of Max are getting clamped unless I choose the “premultiply alpha” option. This happens no matter whether I choose 32bit (full float) or 1/2 float, or realpixel RGB data. They are not clamped in the VFB, but when saved and reloaded they are.

This makes no sense to me, but is that normal or some kind of glitch?

Thanks,
b

2

This seems to be how the 3ds Max .exr writer works; you need to turn on the “Premultiplied alpha” to keep the HDR information.

Best regards,
Vlado

3

I’m not on my workstation right now, but does this affect saving channeled EXRs via the .vrimg option (changing .vrimg to .exr)? There’s not premult option since there’s no EXR pop-up dialog…

4

It does not affect these .exr files, since V-Ray writes them directly without going through the 3ds Max .exr saver; they always have premultiplied alpha on anyways.

Best regards,
Vlado

5

Can you get .exr un-premultiplied when converting from .vrimg?

/p