/YZGI

An implementation of some Global Illumination algorithms, using C/C++

Primary LanguageC++

YZircon's Global Illumination

An implementation of useful GI Algorithms, using C/C++

The sphere and tall box in the left image use microfacet material, while the other objects use diffuse material. It was rendered in 4142 seconds at 1024 samples per pixel (spp).

The sphere and tall box in the middle image use material based on the Fresnel reflection equations, while other objects use diffuse material. And it was rendered in 3582 seconds at 1024 spp.

The left sphere in the right image uses mirror material, and the right sphere uses glass material, while other objects use diffuse material. It was rendered in 4382 seconds at 1024 spp.

All of the images were rendered by YZGI.

Features (Working now)

Model

.obj/.mtl

Rendering

  • Path-Tracing
  • Photon Mapping

Materials

  • Lambert Diffuse BRDF

  • Pure Specular BRDF

    • Fresnel Equation Based

  • Glass BSDF

    • Combination of pure reflection and pure refraction.

  • Microfacet BRDF

    • Cook Torrance GGX

Sampling

  • Multiple Importance Sampling

Color Space

  • By default, colors are defined in the linear sRGB/Rec.709 color space

  • You can adjust according to your needs, but it is recommended to ensure that all colors in the entire renderer are defined in the same color space

  • And make sure it's a linear color space to get rid of physical errors

Build & Run

Source Files

Filename Feature
Core/main.cpp Program Core
Core/Renderer.* Renderer Core
Core/Material.* Class Material, defined by BSDF
Core/Texture.* Class Texture
Core/Sampler.* Class Sampler, used to sample from Texture
Core/Ray.hpp Just a Ray
Core/Scene.* Scene
Core/Intersection.hpp An Intersection
Core/Triangle.hpp Triangle and Mesh
Core/global.hpp Some Global Functions
Core/Integrator.hpp The public class of Integrators
Core/Bounds3.hpp 3D Bounding Box
DS/BVH.* BVH Accelerating Data Structure
DS/KDTree.* K-D Tree Accelerating Data Structure
Integrators/PathTracing.* Simple Path Tracing Integrator
Integrators/PhotonMapping.* Photon Mapping Tracing Integrator

Classes

Name Dependency Feature
Renderer Scene Main Renderer
Material Texture(TBD), Sampler(TBD) Material
Scene Ray, Object Scene
Object None Virtual base class for all kinds of model object
Texture TBD Texture
Sampler TBD Sample the texture
Ray None Just a Ray
Intersection Object, Material An Intersection
Triangle Object A Triangle
Mesh Triangle, Object A set of Triangle, with a bounding box
BVH Object,Ray,Intersection,Bounds3 An Accelerating Data Structure stores Objects in Scene
Bounds3 None Bounding Box
Integrator Ray, Scene Public Class of Integrators
PathTracingIntegrator Ray, Intersection, Scene Implementation of Path Tracing Integrator

Resources

3rd Party Libraries

  • Eigen, a C++ template library for linear algebra: matrices, vectors, numerical solvers, and related algorithms, https://gitlab.com/libeigen/eigen
  • OBJ-Loader, A C++ OBJ Model Loader that will parse .obj & .mtl Files into Indices, Vertices, Materials, and Mesh Structures, https://github.com/Bly7/OBJ-Loader, I modified some of them to support more descriptions in the obj file, the new code follows the license of this project.
  • stb, single-file public domain(or MIT License) libraries for C/C++, https://github.com/nothings/stb

Models