# Advanced WebGL - Part 3: Irradiance Environment Map

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.

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.

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.

Since all the excitement about Minecraft I wondered what nice rendering effects could be done in such a restricted environment. I have decided to pursue that avenue of research and a variety of techniques will be presented in the following article.

I bought a new graphics card which is OpenGL 4.1 compatible. And since tessellation is hot, this article explains how to use tessellation to LOD large terrains easily.