Path Tracer

An importance sampled path tracer, supports Phong / Dielectric / Metal material and various Monte Carlo effects.

Build Instructions:

• This project uses CMake to build and is correctly built under M1 macOS environment. The C++ standard is set to C++ 17.

• Once CMake is installed, use below commands to build with CMake.

• This project uses OpenMP for parallization, for ARM Mac users, please refer to this [post][https://stackoverflow.com/questions/71061894/how-to-install-openmp-on-mac-m1] .

• Add GL_SIMD to compile definition to enable SIMD (for vec and matrix class).

mkdir build
cd build
cmake ..
make .

File Structures:

./src
├── ./src/base
│   ├── ./src/base/camera.cpp
│   ├── ./src/base/camera.hpp
│   ├── ./src/base/compound.hpp
│   ├── ./src/base/framebuffer.cpp
│   ├── ./src/base/framebuffer.hpp
│   ├── ./src/base/light.cpp
│   ├── ./src/base/light.hpp
│   ├── ./src/base/lightList.hpp
│   ├── ./src/base/material.hpp
│   ├── ./src/base/medium.hpp
│   ├── ./src/base/object3D.cpp
│   ├── ./src/base/object3D.hpp
│   ├── ./src/base/objectList.cpp
│   ├── ./src/base/objectList.hpp
│   ├── ./src/base/primitive.cpp
│   ├── ./src/base/primitive.hpp
│   ├── ./src/base/ray.hpp
│   ├── ./src/base/texture.cpp
│   ├── ./src/base/texture.hpp
│   └── ./src/base/vertex.hpp
├── ./src/deprecated
│   └── ./src/deprecated/raytracer.cpp
├── ./src/external
│   ├── ./src/external/sse2neon.h
│   ├── ./src/external/stb_image.h
│   └── ./src/external/stb_image_write.h
├── ./src/method
│   ├── ./src/method/analytical_illumin.hpp
│   ├── ./src/method/maxdepth_naive.hpp
│   ├── ./src/method/maxdepth_shadowray.hpp
│   ├── ./src/method/roulette_naive.hpp
├── ./src/probs
│   ├── ./src/probs/hittablePDF.hpp
│   ├── ./src/probs/mixedPDF.hpp
│   ├── ./src/probs/pdf.hpp
│   └── ./src/probs/random.hpp
├── ./src/scene_func
│   ├── ./src/scene_func/renderManager.hpp
│   └── ./src/scene_func/scenes.hpp
├── ./src/unit_test.cpp
├── ./src/unit_test.hpp
├── ./src/main.cpp
└── ./src/utils
    ├── ./src/utils/aabb.hpp
    ├── ./src/utils/bvh.hpp
    ├── ./src/utils/colors.hpp
    ├── ./src/utils/commonMaterials.hpp
    ├── ./src/utils/matrix.hpp
    ├── ./src/utils/objectTransform.cpp
    ├── ./src/utils/objectTransform.hpp
    ├── ./src/utils/orthoBasis.hpp
    ├── ./src/utils/pattern.hpp
    ├── ./src/utils/quat.hpp
    ├── ./src/utils/scene_io.cpp
    ├── ./src/utils/scene_io.hpp
    ├── ./src/utils/timeit.hpp
    ├── ./src/utils/transformations.hpp
    └── ./src/utils/utility.hpp

• src/base contains base classes
• src/utils contains common materials, utility functions and classes
• src/probs contains PDF related functions and classes
• src/method contains rendering methods
• src/main.cpp contains the main function
• src/scene_func contains a rendering manager, and all scene infos are written in scenes.hpp
• All rendering settings except light sampling number, are written in the scenes.hpp files. Light sampling numbers are given in src/method/maxdepth_naive.hpp as macro define.

Features:

• Different Rendering Methods:

  • Analytical Direct Illumination: This one provides an analytical direct lighting solution if the light is polygonal and there’s no occluder.

  

  • Shadowray Path Tracer: This one uses shadowray method to separate direct and indirect illumination.
  • Max Depth Naive: This one is the basic importance sampled path tracer, with a max depth limit.
  • Roulette Naive: This one is the basic importance sampled path tracer, uses Russian Roulette method for unbiased estimation.
  • Whitted: This one is the traditional Whitted-style ray tracing. See src/deprecated/whitted.hpp

  

• Importance Sampling:

  • The path tracer uses an importance sampling strategy, a mixed PDF of cosine and light sampling. The light sampling can be arbitrary numbers.

  

• Monte Carlo and Post-processing effects:

  • The path tracer supports DoF, motion blur. Image filtering and tone-mapping.

Whitted, 16x16 spp

TODO:

• Port whitted algorithm to the same API
• Bidirectional Path Tracing implementation
• Image-based lighting