Auto Exposure

[glorybound]

I have not been able to auto expose my interiors. I mean, not anything I can use. When I auto expose it exposes the exterior and the interior is dark. Did I read somewhere that you can pick somewhere in the VFB where you would like it to expose? Maybe that was a dream.

[^Lele^]

You can't "pick", but you can essentially select with a render region, render the selection to expose to that, and then transfer the exposure to the camera(s).

[glorybound]

Perfect, thanks! I was confusing the DOF with Exposure. Can't you pick in the VFB for DOF?

[^Lele^]

Yep!
Focus can be picked in the VFB when doing IPR, but then that's a point.
We wouldn't be exposing very right if we did the maths on a point alone, that's why it's a bit more convoluted for exposure (although, it's much the same problem as it is with real cameras).

[Nicinus]

Very clever exposing to a render region, thanks for the tip. So just to confirm, auto-exposure only considers whats in a render region and not the whole image if a render region is present?

[^Lele^]

Yes: the exposure is calculated during the LC phase.

[glorybound]

Yep, region render is the bomb with auto exposure.

[^Lele^]

I forgot to add, although it may be obvious to most: Because it's calculated during the LC phase, it only takes rendering that part (even a fairly low subdivs one, even cropped.) to get an exposure out of V-Ray.
So, generally a few seconds if that.

[Nicinus]

Very cool.