Raytracer - 3D Scene Renderer 🎨✨

A real-time 3D raytracing renderer built with C++ and SDL2. Create and visualize stunning 3D scenes with realistic lighting, shadows, and reflections. Interact with the scene using mouse and keyboard controls.

🎯 What Does It Do?

This raytracer renders 3D scenes in real-time with:

• 3D Rendering: Visualize complex 3D scenes with spheres, planes, and other objects
• Realistic Lighting: Accurate light simulation with shadows and reflections
• Interactive Controls: Rotate, zoom, and navigate through the scene
• Real-Time Updates: See changes instantly as you interact
• Ray-Object Intersection: Precise mathematical calculations for realistic rendering
• Color and Materials: Different materials with varying properties
• Ambient Occlusion: Soft shadows for depth perception

👤 Who Is It For?

• Computer graphics students learning raytracing
• Game developers understanding rendering techniques
• 3D artists exploring rendering algorithms
• Programmers interested in graphics programming
• Anyone fascinated by computer-generated imagery

🚀 How to Use

Prerequisites

• C++ Compiler (g++ or clang)
• SDL2 Library - For window management and rendering
• Make - Build automation tool

Installation

1. Install SDL2

macOS:

brew install sdl2

Ubuntu/Debian:

sudo apt-get update
sudo apt-get install libsdl2-dev

Fedora:

sudo dnf install SDL2-devel

Windows:

• Download SDL2 development libraries from SDL2 Downloads
• Extract and configure in your project

2. Clone and Build

# Clone the repository
git clone https://github.com/mohammedhrima/Raytracer.git
cd Raytracer

# Build the project
make

# This creates the executable 'exec'

Running the Raytracer

./exec

A window will open displaying the rendered 3D scene.

🎮 Interactive Controls

Mouse Controls

Rotate the Scene:

• Left-click and drag: Rotate the camera around the scene
• Move mouse left/right: Rotate horizontally
• Move mouse up/down: Rotate vertically

Zoom:

• Scroll wheel up: Zoom in (get closer to objects)
• Scroll wheel down: Zoom out (move away from objects)

Keyboard Controls

Navigate the Scene:

• ↑ (Up Arrow): Move camera upward
• ↓ (Down Arrow): Move camera downward
• ← (Left Arrow): Move camera left
• → (Right Arrow): Move camera right

Exit:

• ESC: Close the application

✨ Features

Raytracing Techniques

Ray Generation:

• Generates rays from camera through each pixel
• Calculates ray direction based on camera position and orientation

Intersection Testing:

• Ray-sphere intersection
• Ray-plane intersection
• Efficient intersection algorithms

Lighting Model:

• Diffuse lighting (Lambertian reflection)
• Specular highlights
• Ambient lighting
• Shadow rays for realistic shadows

Color Calculation:

• RGB color mixing
• Material properties (color, reflectivity)
• Light intensity calculations

Scene Elements

The default scene includes:

• Multiple spheres of different sizes and colors
• Ground plane
• Light sources
• Camera with adjustable position

Performance

• Real-time rendering at interactive frame rates
• Optimized intersection calculations
• Efficient memory management

🛠️ Technical Stack

• C++98: Core programming language
• SDL2: Simple DirectMedia Layer for graphics
• Mathematics: Vector math, ray equations, intersection algorithms
• Make: Build system

📁 Project Structure

Raytracer/
├── Makefile              # Build configuration
├── README.md             # This file
├── Screenshot.png        # Preview image
├── header.hpp            # Header files and declarations
├── main.cpp              # Entry point and main loop
├── math.cpp              # Vector and matrix mathematics
├── raytracing.cpp        # Core raytracing algorithms
├── window.cpp            # SDL window management
├── new.cpp               # Memory management
└── SDL/                  # SDL2 header files
    ├── SDL.h
    ├── SDL_events.h
    ├── SDL_video.h
    └── ... (other SDL headers)

🔧 Building and Compilation

Build Commands

# Compile the project
make

# Clean build files
make clean

# Rebuild everything
make re

Compilation Details

The Makefile compiles these source files:

• main.cpp - Application entry point
• math.cpp - Mathematical operations
• raytracing.cpp - Raytracing algorithms
• window.cpp - Window and event handling
• new.cpp - Memory management

Flags used:

• -std=c++98 - C++98 standard
• -Wall -Wextra -Werror - Strict warnings
• -lSDL2 - Link SDL2 library

🎨 Understanding Raytracing

How Raytracing Works

1. Camera Setup: Define camera position and viewing direction
2. Ray Generation: For each pixel, create a ray from camera through pixel
3. Intersection Testing: Check if ray hits any objects in scene
4. Shading: Calculate color based on:
   • Object material
   • Light sources
   • Shadows
   • Reflections
5. Pixel Coloring: Set pixel to calculated color

Ray Equation

Ray(t) = Origin + t * Direction

Where:

• Origin = Camera position
• Direction = Ray direction through pixel
• t = Distance along ray

Sphere Intersection

Solving the equation:

|Ray(t) - SphereCenter|² = SphereRadius²

Results in a quadratic equation that determines if and where the ray hits the sphere.

🎓 Learning Outcomes

This project demonstrates:

• Ray-object intersection algorithms
• 3D vector mathematics
• Lighting models and shading
• Real-time graphics programming
• SDL2 for window management
• Event handling (mouse, keyboard)
• Performance optimization

🔧 Customization

Modify the Scene

Edit raytracing.cpp to:

• Add more spheres
• Change sphere positions and sizes
• Modify colors and materials
• Add different light sources
• Change background color

Adjust Camera

Edit main.cpp to:

• Change initial camera position
• Modify field of view
• Adjust movement speed
• Change rotation sensitivity

Enhance Rendering

Possible improvements:

• Add more object types (cubes, cylinders)
• Implement reflections and refractions
• Add texture mapping
• Implement anti-aliasing
• Add depth of field effects

📊 Performance Tips

Optimize Rendering:

• Reduce window resolution for faster rendering
• Limit number of objects in scene
• Use bounding volumes for complex objects
• Implement spatial data structures (BVH, octree)

Improve Quality:

• Increase ray samples per pixel
• Add more light bounces
• Implement global illumination
• Use higher precision calculations

🐛 Troubleshooting

SDL2 not found:

# Verify SDL2 installation
sdl2-config --version

# If not found, reinstall SDL2

Compilation errors:

# Clean and rebuild
make clean
make

Window doesn't open:

• Check if SDL2 is properly installed
• Verify display is available
• Check for error messages in terminal

Slow performance:

• Reduce window size
• Simplify scene (fewer objects)
• Close other applications

📈 Future Enhancements

• Add more primitive shapes (cubes, cylinders, cones)
• Implement reflection and refraction
• Add texture mapping
• Implement anti-aliasing (supersampling)
• Add global illumination
• Support for loading 3D models (OBJ files)
• Path tracing for photorealistic rendering
• GPU acceleration with CUDA or OpenCL
• Scene file format for easy scene creation
• Real-time scene editing

🤝 Contributing

Contributions welcome! Great project for learning:

• Computer graphics
• Raytracing algorithms
• C++ programming
• SDL2 library

📚 Resources

Learn More About Raytracing:

• Ray Tracing in One Weekend
• Scratchapixel - Ray Tracing
• SDL2 Documentation

Mathematics:

• Vector operations
• Ray-sphere intersection
• Lighting equations (Phong, Blinn-Phong)

📄 License

This project is open source and available for educational purposes.

🙏 Acknowledgments

• SDL2 team for the excellent graphics library
• Computer graphics community for raytracing resources
• Classic raytracing papers and books