ChanGameEngine

This is my personal game engine, which is a kind of experiment lab for me. I've started this project as the game engine project, but it's just becoming my experiment. However, I still have the goal to make my own game engine.

the program structure and the build system of this project is not good because I didn't know anything about those topics when I started this project. But I've experienced the game engine development in the company. Now, I am ready to change this project. Before doing that, I can show what I did with this project.

2018.08 ~ 2019.01

I started this project for my portfolio to get a job as game engine / graphics programmer. I studied the math, OpenGL, game physics and so on to make my own game engine. During this period, I implemented the basic graphics and physics parts of the game engine. This is the final scene I made with my engine :

Here is the editing gif of the scene :

you can see the video of this here.

While I was doing this project, I implemented these things:

Graphics

• The graphics engine is based on the deferred shading. All of objects in game world will be drawn by the technique.
• PostProcessing : HDR, Bloom, SSAO.
• Terrain Rendering with Perlin noise and height map (you can see the terrain rendering and physics

Light

• Editing light properties : Position, Direction, Ambient/Diffuse/Specular Color, Attenuation factors, light radius.
• The types of light : Directional, Point, and Spot light.
• Range Visualizer for each light type
• Shadow cast for each light type
• Editing the shadow frustum for each light type

Physics

• Most of physics theories and implementations are based on the "Game Physics Engine Development" Book. This book does not solve a jitter problem caused by its implementation. So it changed my research direction toward Box2D and BulletPhysics Library to learn a valid physics engine implementation. So, I studied the Erin Catto's GDC presentation for Sequential Impulse Constraint Solver and his implementation in my other repository. And the video about it is here.
• And other codes such as Broad Phase, DynamicAABBtree, Ray Picking are based on Box2D and BulletPhysics Library.
• Terrain Physics between terrain triangles and spheres.

2020.12 ~ 2021.01

I had stopped this project after I got the job as a game engine programmer. But I have an interest in the high quality rendering, especially using ray tracing. So, I got enough time at this period to study a little of the ray tracing. This is the simple scene I made with the ray tracing :

I Implemented these for this ray-traced scene :

• Rendering Equation : I'm using the Graphics Codex to learn the rendering equation. And I also refer to the sample code provided with the Graphics Codex in G3D Innovation Engine.
• Primitive Intersection : Sphere, Plane, Ray, Line Segment, Triangle. I referred to the RTCD to implement all of the intersections.
• Bounding Volume Hierarchy : In order to accelerate the ray intersection, I used the Dynamic AABB Tree, which I implemented by referring to the box2D code.

In addition to the above, I used the threads to accelerate the ray tracing by separating the pixels with some threads.

Because I'm using the Graphics Codex to improve my graphics ability, I am going to study BSDF, Path Tracing, Photon Mapping, and so on. Before going deeper on this, I realized that I don't have enough base knowledge on statistics. So I've decided to study it. After that, I can restart this ray tracing work.