Computer Graphics Project --- Ray Tracing

Requirements

• GNU GCC C++ compiler 5.4 (at least support C11)
• CMake 3.5+
• OpenCV (optional)
• GLFW3 - OpenGL (optional)

To compile correctly, at least one of OpenCV and OpenGL is needed for rendering, and you can specify the option in the CMakeLists.txt file.

Instruction

0. Clone the repository

   git glone [email protected]:lw396285v/raytrace.git
   cd raytrace

1. Check CMakeLists.txt, and set build option, for example if you only have OpenGL library installed, you can set:

   set(BUILD_WITH_OPENGL 1) # which means you have OpenGL library
   set(BUILD_WITH_OPENCV 0) # which means you don't have OpenCV library

2. Then you can run these commands in the source directory to build

   mkdir build
   cmake ..
   make all -j8 
   # on Windows it may be slightly different, after "cmake ..", you may need to use Visual Studio to open the project and build.

3. After building, you will find 4 executable files

   tracer
   tracer_double
   tracer_single
   UnitTest

4. To visualize the result, you can run each executable like

   # command : [excutable name] [rendering method]
   # for example
   tracer_double opencv;
   UnitTest opengl;

   but remember, only OpenCV Rendering will save a PNG image snapshot under its root directory.

Result

Each executable will generate a scene, and they are shown here

UnitTest

This is a simple scene, which include 3 planes, 1 sphere and 1point light source. The rays are recursively traced 2 times. All objects' material use Phong reflection model. The differences are:

1. The shininess term is different. It is obvious that the sphere is more shiny.
2. The planes and the sphere have different mirror property (reflection).
3. The sphere has glass property (transparency).

tracer

This scene contains 2 sphere, 1 cylinder, 1 octahedron and 5 planes, with 1 point light source. The rays are recursively traced 3 times.

1. only the front sphere is transparent.
2. All objects except the left, back and right planes have mirror property.
3. Due to different ambient light terms and reflect behaviors (specular and diffuse term), the colors of the objects are different.
4. shininess terms are different

But with one point light source, the shadow is sharp.

tracer_single

Compare to tracer , tracer_single has a different light source. In face, 9 point light sources are used to simulate 1 circle light source. and we can find that the shadow become soft.

tracer_double

I add another circle light source (In fact, there are total 12 point light source) in the scene. Maybe it's too bright?

Code structure

Problems encountered

During the coding procedure, I met many math problems (mainly solid geometry). And I use MATLAB to test my calculation and it works well.