In part 2 of this series I explained about how to get the sky. This entry is about how to compute an irradiance environment map from this cubemap.
I was interested in how many people have support for WebGL and what features they do support. My Demos reported issues to me as well as hardware capabilities. This gives me a good way to analyze what I'm doing right or wrong.
In Part 1 of this howto, I introduced my demo. In this part I'm going to talk about how to make the sky. The demo also computes an irradiance map and applies it to the cube. I'm going to talk about this in Part 3.
WebGL is now enabled by default in both Firefox 4.0 and Chrome 10.0, so I thought I give it a try and see what I can get out of it. The goal was to render some simple terrain, nice looking sky and waving grass. In this part of the description I will give the overview of how that works.