
Fixed the refraction part and added multi threading, spp = 256.

Add caustics map, SPP = 512, min_bounces = 10, more bounces using Russian roulette.

Add caustics map, SPP = 4, min_bounces = 10, more bounces using Russian roulette.

Implement MIS with balanace heuristic, SPP = 4, min_bounces = 10, more bounces using Russian roulette.

Implementing MIS, SPP = 8, max_bounces = 10