Thanks for the explanation. That makes sense. Neat stuff.

Btw there is proprietary/coprighted unity shader code cut and pasted into this, someobe even copied the original comments from the unity shaders. For example search for "DecodeLightmapRGBM" in the below source code, which is from the demo - that code and others are copied:

https://gist.github.com/bhouston/1c3c6835ca9766571f07ad0126d...

Here is some unity source code to compare against: https://gist.github.com/nicloay/8d2ae254a77de58bb42b9009b4cf...