[brodie_geers]

True. Given that reasoning I could see why caustics could be a problem with HDRs. But I seem to recall a time when we were advised to actually export your phys sky as an hdr as it would increase render speeds. Am I remembering correctly?

-Brodie

[tom]

But I seem to recall a time when we were advised to actually export your phys sky as an hdr as it would increase render speeds. Am I remembering correctly?

Right. But, it's just a workaround, not a true replacement. Otherwise we'd do that transparent to user.

[Tim Ellis]

Here's my old tests concerning caustics & ibl from phys sky map during v1.x testing:-

Caustics_validator_IBLmatch_01.jpg

Scatter was added in mxcl to the illumination hdr after it was saved from MXST. This helped to produce more caustics.

I haven't tested this again with 2.5.1 but when I get chance I will try and run through them again.

Tim.