AovDepthTracer - sky is black not white


The sky has an incorrect depth value; returns infinity not 0 (or is that the other way round... Probably) in either case it's the wrong colour.

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Work around is to use transparent sky. But this requires PNG export and reduces information which could be used.

Start by reproducing the black-sky result in AovDepthTracer and inspect how the sky depth value is handled. Confirm whether the sky should use zero or infinity, then verify that the rendered sky has the expected colour without relying on the transparent-sky workaround.

Written by the indexing model from the issue text.