Gluttony - Ray Tracer

A simple ray tracer with BVH acceleration, built with C++ and OpenGL (OpenGL only for quick iteration, switching to Vulkan later). This project starts as a real-time renderer, BVH visualization tools, and shader tester. But after the renderer is matured this will become a Game Engine.

Current Features

• BVH Acceleration: Spatial acceleration structure for fast ray-scene intersection
• Real-time Rendering: Interactive rendering with camera controls
• Debug Visualization: Multiple BVH visualization modes:
  • Bounding box hierarchy
  • Bounding Box intersection test counts
  • Triangle intersection test counts
• Shader Hot-Reloading: Edit shaders and see changes in real-time
• Mesh Import: Supports most common mesh formats with automatic optimization
• Performance Metrics: Detailed BVH statistics and rendering timings

Future plans

• GPU ray tracing via compute shaders
• Physically-based materials

Getting Started

Prerequisites

• CMake 3.20+
• C++20 compatible compiler
• OpenGL 4.6
• GLFW
• GLEW
• Assimp
• MeshOptimizer

Building

git clone git@github.com:Mich-Dich/gluttony.git
cd gluttony
vendor/premake/premake5 gmake2 && make -j

Running

replace <your_arcetecture> with the arcetecture you want to use, typicly only one available. eg: Debug-linux-x86_64

bin/<your_arcetecture>/gluttony_editor/gluttony_editor

Controls

• Mouse Right Button + WASD/space/left Control: Move camera
• Mouse Right Button + Mouse: Look around
• Mouse Right Button + Mouse wheel: Move faster/slower

BVH Visualization Modes

Toggle in the debug UI:

1. Bounding Boxes: Visualize BVH hierarchy
2. Box Tests: Show intersection test counts
3. Triangle Tests: Visualize triangle traversal

Key Components

BVH Implementation

• Compact BVH node structure (32 bytes per node)
• SAH (Surface Area Heuristic) for optimal splits
• Binned SAH evaluation for performance
• Multi-threaded BVH construction

Rendering Pipeline

• SSBOs for geometry data transfer
• Optimized triangle intersection

Performance

Typical performance on my NVIDIA GeForce RTX 3060 Laptop:

• BVH build time: 15-40ms for complex meshes
• 2-5ms BVH traversal for primary rays

Contributing

Contributions are welcome! Please open an issue or pull request for any:

• Bug fixes
• Performance improvements
• New features
• Documentation updates

License

MIT License - see LICENSE for details.