ray-tracing

Features

• Phong Model
• Phong Shading
• Multi-threaded Rendering
• Spatial Subdivision Using K-d Tree
• A Graphics User Interface for Development
• Load Scene from .json File
• Save Rendered Image to .png File
• Effects
  • Soft Shadow
  • Transparency
  • Reflection
  • Refraction
  • Diffusive Reflection
  • Color Bleeding
  • Texture

Build and Run without GUI

To run the ray tracer, you need to install libpng first:

ubuntu$ sudo apt install libpng-dev
mac$ sudo brew install libpng

Then build and run:

$ git clone --recursive https://github.com/abcdabcd987/ray-tracing.git
$ mkdir -p build && cd build
$ cmake -DGUI=OFF .. && make
$ ./raytracer-cli
usage: ./raytracer-cli [options]
options:
   -w <INT>        image width
   -h <INT>        image height
   -d <INT>        ray tracing depth
   -r <INT>        number of diffuse reflect samples
   -l <FLOAT>      number of light samples per unit volume
   -j <INT>        number of thread workers
   -o <STRING>     path to output png image
   -f <STRING>     path to scene json

Build and Run with GUI

To run GUI, you need to install GLFW3 and SDL2 first:

ubuntu$ sudo apt install freeglut3-dev libsdl2-dev libpng-dev
mac$ brew install glfw sdl2 libpng

Then build and run:

$ git clone --recursive https://github.com/abcdabcd987/ray-tracing.git
$ mkdir -p build && cd build
$ cmake .. && make -j
$ ./raytracer-gui

Run GUI on Remote Server

Remote OpenGL program can be forwarded to local using xpra.

server$ sudo apt install xpra
server$ xpra start :100
server$ export DISPLAY=:100
server$ ./raytracer-gui
server$ xpra stop

ubuntu-client$ sudo apt install xpra
ubuntu-client$ xpra attach ssh:host:port:100
mac-client$ brew cask install xpra
mac-client$ /Applications/Xpra.app/Contents/MacOS/Xpra attach ssh:host:port:100

Scene 1

$ ./raytracer-cli -w 2400 -h 1800 -d 5 -r 1 -l 1000 -j 8 -o ../rendered/scene1.png -f ../scene/scene1.json
========== scene information ==========
                primitives    4
                 triangles    246354
=========== render settings ===========
                     width    2400
                    height    1800
               trace depth    5
   diffuse reflect samples    1
  light samples per volume    1000.000
                   workers    8
rendered 4320000/4320000 pixels using 8 workers in 299.432s...done

• Soft Shadow: Look at shadows!
• Transparency: You can see through the bunny!
• Reflection: The back wall is actually a mirror.
• Refraction: Not in this scene. (actually, the transparent bunny is because of refraction.)
• Color Bleeding: Not in this scene.
• Texture: The ground, the back wall and the watermelon are textured.
• Phong Shading: You can see the teapot looks better than it would if rendered with flat shading.

Scene 2

$ ./raytracer-cli -w 2400 -h 1800 -d 5 -r 256 -l 1000 -j 8 -o ../rendered/scene2.png -f ../scene/scene2.json
========== scene information ==========
                primitives    7
                 triangles    100966
=========== render settings ===========
                     width    2400
                    height    1800
               trace depth    5
   diffuse reflect samples    256
  light samples per volume    1000.000
                   workers    8
rendered 4320000/4320000 pixels using 8 workers in 2059.191s...done

• Soft Shadow: Look at shadows!
• Transparency: Not in this scene.
• Reflection: The back wall is actually a mirror.
• Refraction: The ball acts like a magnifier.
• Color Bleeding: Look at the ball and the ground.
• Texture: The back wall.
• Phong Shading: You can see objects looks better than it would if rendered with flat shading.

Thanks to

• http://www.flipcode.com/archives/Raytracing_Topics_Techniques-Part_1_Introduction.shtml
• https://www.scratchapixel.com/
• https://github.com/ppwwyyxx/Ray-Tracing-Engine
• (and also you many want to refer to ref: comments in the code)