Now that I am getting my head around Solaris and Karma, I wanted to revisit the cloud study I did and rework it from the ground up. The undocumented thing I had to figure out this time was how to get the HDRI that is lighting the scene to show up in the render. Its buried under Dome Light > Karma > Render light geometry. And the freaking manual just has a blank section for Karma….. like really?