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I don't know if this is necessarily a problem, but to me it is unexpected. I have a simple scene with 8 instanced Vray Lights. They are set to a multiplier of 500. I have a physical camera set to ISO of 6400.
If I render the scene at AA 1,6, it renders quickly.
If I change the scene so that the lights' multiplier is 8000 (16x higher) and set the ISO to 400 (16x lower), the scene takes twice as long to render (due to more refined AA). The lighting levels appear unchanged as you'd expect, but I don't understand why the antialiasing is acting differently (as is evident in the VraySampler element).
I would expect that Vray analyzes the frame in a relative way -- so that doubling exposure and halving lighting would result in the exact same render with the same render time but clearly there is some absolute value that is also being factored in. Why does the AA seem to be tied to overall lighting level even if the camera exposure is adjusted to compensate for any lighting changes?
I was testing this because I've noticed when I try to use night-time exposures (matching what you might use in the real world) I have a harder time with noise and have to use much higher AA than I normally would.
If I render the scene at AA 1,6, it renders quickly.
If I change the scene so that the lights' multiplier is 8000 (16x higher) and set the ISO to 400 (16x lower), the scene takes twice as long to render (due to more refined AA). The lighting levels appear unchanged as you'd expect, but I don't understand why the antialiasing is acting differently (as is evident in the VraySampler element).
I would expect that Vray analyzes the frame in a relative way -- so that doubling exposure and halving lighting would result in the exact same render with the same render time but clearly there is some absolute value that is also being factored in. Why does the AA seem to be tied to overall lighting level even if the camera exposure is adjusted to compensate for any lighting changes?
I was testing this because I've noticed when I try to use night-time exposures (matching what you might use in the real world) I have a harder time with noise and have to use much higher AA than I normally would.
