Spherical Harmonics Playground
This is a simple application that loads an OBJ file and an environment map and calculates & displays the corresponding 3rd order spherical harmonics coefficients for it. The coefficients can also be modified at runtime to see the effect of each coefficient.
Linux dependencies for glfw: xorg-dev libgl1-mesa-dev
git clone --recursive https://github.com/ands/spherical_harmonics_playground.git cd spherical_harmonics_playground cmake . make ./playground
dickyjim has collected various resources regarding spherical harmonics on his blog.