We reproduct the main algorithm of the paper "Hierarchical Russian Roulette for Vertex Connections" by Yusuke Tokuyoshi et al. (2019). The renderer code framework is from glsl-pathtracer.
Paper at https://yusuketokuyoshi.com/papers/2019/Hierarchical_Russian_Roulette_for_Vertex_Connections.pdf .
We add a naive bidirectional path tracer, and implement the HRRVC algorithm in the bidirectional path tracer. We also add a path tracer for comparison. The enviroment map and volume rendering are not implemented.