Bugs to fix:

- @AnastaZluk example 40 not compiling
- @AnastaZluk persistent WG flickering and camera & light not updating
- @karimsayedre no difference between Rectangle Solid Angle and Rectangle Area sampling
- @keptsecret part the glass sphere facing away from the light getting wrong lighting
- @Przemog1 RWMC no more black screen and get it working like here https://cg.ivd.kit.edu/publications/2018/rwmc/tool/rw.html (with noticeable results)

Author: devshgraphicsprogramming