Third of three tests using Bryce 6.1 IBL. Thumbnail shows the .HDR image used.

Since IBL currently doesn't work with Volumetrics, I went back to a pre-Volumetric trick of stacking 2D, World space cloud planes very close together. In this scene there are 20 cloud planes set 1 BU apart.

IBL set to 64 lights and rendered with Normal AA.

Render time: aprox 16 hours.

MacPro dual-dual 2.5 GHz, High Priority