3D Graphics Demo Program

Solo Project
March 2023 - May 2023
Skills Utilized: C++, OpenGL, JSON5, ImGUI, Graphics Programming, Game Engine Programming

Introduction

This was a course project exploring various graphics techniques. I implemented Toon shading, Shadow mapping, Noise-based terrain generation, Procedural mesh generation, Catmull-Rom splines, and Hermite curves.

Since the project required handling multiple scenes and shaders, I developed a simple data-driven engine that allowed assets like shaders, textures, and models to be registered and scenes to be configured dynamically at runtime through data modifications.

Showcase

↑ Toon Shading Showcase

↑ Shadow Mapping Showcase

Technical Highlights

Toon shading

This was the most enjoyable topic. The technique involves mapping the difference between the normal vector and light direction into discrete steps rather than a smooth gradient, creating a cel-shaded look seen in some games. Implementing it myself was fun, and the unique look and feel were refreshing.

One interesting challenge was mitigating aliasing artifacts at the boundaries of shading steps. A naïve implementation results in noticeable stair-step artifacts along the edges. To smooth these transitions, I used fwidth in the shader to blend the two colors over a few pixels near the boundary, reducing the harshness of the effect.

Shadow mapping

Generating shadow maps was also an interesting experience. While there are various advanced techniques, I implemented a classic, straightforward method for learning purposes. The scene is rendered from the light’s perspective to create a depth buffer, which is then used to determine shadowed areas based on depth comparisons and normal alignment.

Data-driven engine

Given the project's need for frequent scene and shader modifications, I developed a simple engine to manage objects and scenes efficiently. It automated scene and object handling and allowed assets such as shaders, textures, and models to be configured in a data-driven manner, enabling runtime modifications without recompilation.

↑ The tessellation scene's json5 file

Conclusion

Through this project, I explored various 3D graphics techniques and gained hands-on experience implementing them from scratch. I found toon shading particularly engaging, as it involved both technical problem-solving and aesthetic considerations. Shadow mapping reinforced my understanding of depth-based rendering techniques, while building a simple data-driven engine helped me appreciate the importance of flexible scene management. Overall, this project deepened my understanding of graphics programming and engine architecture.