A CPU based offline Renderer for personal interest and education.

Last Update: 7/4/2024

Features

• Integrator
  • Path Tracing
  • Light Tracing
  • Bidirectional Path Tracing (BDPT)

       Stick closely to veach97. Learning and Coding refer a lot to 
       https://rendering-memo.blogspot.com/2016/03/bidirectional-path-tracing-1-kickoff.html
        
       0. No t == 0 case 
       1. Shading normal asymmetric Bsdf correction ✅
       2. Some problem with Microfacet Transmissive material (when path length <= 5 is fine) ❌ TODO
       

• Matertial:
  • Lambertain Diffuse (cos weighted)
  • Microfacet Reflection and Transmittance (Cook Torrance Model with GGX distribution).
  • Perfect Reflective
  • Perfect Refractive.
  • Unlit. (incompatible with bdpt)
• Sampling
  • Importance Sampling
  • Multiple Importance Sampling
  • Next Event Estimation
• Texture Mapping
  • Albedo/Diffuse Map
  • Normal Map
  • Roughness Map
  • Metallicness Map
• Acceleration
  • BVH default (midpoint)
  • CPU Multi-Threading (std::thread)
• Post Processing
  • Bloom
  • HDR
  • Tone Mapping / Gamma Correction
• Russian Roulette (Throughput) in path tracing

Todo List

• Microfacet refractive/translucent ✅

• BDPT ✅

• don't rely on .ppm image file

• 6/29/2024:

  1.better config file
  
  2.image based lighting
  
  3.Subsurface scattering
  
  4.SAH BVH
  

Usage

      $ ./PathTracing.exe config.txt
   

Develop Environment: MSVC C++17, Visual Studio 2022

cmakelist or makefile of the latest version is TO-DO in the future

Refer to https://github.com/bobhansky/WhittedStyle_Raytracer/blob/main/README.md for more instruction on configuration file.

Sample Result

Cornell Box with 512 samples per pixel

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Contrast

left: Whitted style Ray Tracing (shading with Blinn Phong Model)
right: Path Tracing

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others

upperleft: BSDF sampling                                 upperright: light Sampling

lowerleft: NEE only                                      lowerright: NEE + MIS