Monte Carlo Path Tracer in Unity3D using compute shader

Unity 2018.3.7f1 (win10 64-bit)

Features:

Path Tracing Rendering based on Monte Carlo integration
Emprical BRDF and BTDF
Diffuse, specular, refraction, Fresnel
Hemisphere Sampling, importance sampling
Fuzzy glassy ball

Principle:

Rendering Equation

Monte Carlo Integration

BSDF = BRDF + BTDF

Energy Distribution

BRDF and importance sampling

Importance-Sampling Lambert

Importance-Sampling Phong

BTDF and importance sampling

Importance-Sampling Phong for refraction

Reference:

GPU Path Tracing in Unity – Part 2
Rendering Equation
Monte Carlo Methods in Practice
蒙特·卡罗(Monte Carlo)积分详解
 Using the Modified Phong Reflectance Model for Physically Based Rendering (1994)
Uniform Sampling on unit Hemisphere
Generating uniformly distributed numbers on a sphere
Reflection, Refraction (Transmission) and Fresnel
Webgl中采用PBR的实时光线追踪
 Image-based rendering of spatially-varying BSDF