CGR Raytracer

A C++ raytracer implementation with Blender integration for computer graphics rendering.

Features

• Whitted-style recursive raytracing
• BVH acceleration structure for optimized rendering
• Multiple geometric primitives (sphere, cube, plane, torus, cylinder, cone)
• Composite BRDF shading (Lambertian diffuse + Blinn-Phong specular)
• Hard and soft shadows
• Reflection and refraction with Snell's law
• Texture mapping with UV coordinates
• Antialiasing with multi-sampling
• Glossy reflections
• Motion blur
• Depth of field
• Blender scene exporter

Requirements

• C++20 compatible compiler (g++)
• OpenMP (libomp on macOS)
• Blender (optional, for scene creation)

Building

Build the raytracer:

make

Clean build artifacts:

make clean

Debug build:

make debug

Usage

Basic usage:

./raytracer --scene ASCII/Test1.txt --output Output/result.ppm

With custom settings:

./raytracer --scene ASCII/Test1.txt \
  --output Output/result.ppm \
  --resolution 1920 1080 \
  --samples 16 \
  --max-depth 5

Available options:

• --scene <file> - Input ASCII scene file
• --output <file> - Output PPM file
• --resolution <w> <h> - Image resolution
• --samples <n> - Antialiasing samples per pixel (1 = no AA, 4+ = AA enabled)
• --max-depth <n> - Maximum ray recursion depth
• --enable-textures / --disable-textures - Enable/disable texture mapping (default: enabled)
• --soft-shadows <n> - Enable soft shadows with n samples
• --glossy-reflection <n> - Enable glossy reflections with n samples
• --motion-blur <n> - Enable motion blur with n temporal samples (0 to disable)
• --disable-motion-blur - Disable motion blur completely
• --depth-of-field <a> <d> - Enable DOF with aperture f-stop and focal distance
• --disable-dof - Disable depth of field
• --light-intensity <f> - Global light intensity multiplier (default: 0.2)
• --ambient-light <f> - Ambient light factor (default: 1.0)
• --threads <n> - Number of rendering threads (0 = auto-detect)
• --log-level <level> - Set log level (debug, info, warn, error)

Note: The following features are always enabled and cannot be disabled:

• BVH acceleration structure
• Shadows (with transparency support)
• OpenMP parallelization
• Fresnel reflections for glass materials
• Normal and bump mapping (when textures provide them)

Makefile Targets

Build Targets

make            # Build the raytracer (default)
make clean      # Remove build artifacts
make debug      # Build with debug symbols

Test Targets

make test-1     # Render Test1 scene with optimal settings
make test-2     # Render Test2 scene with optimal settings
# ... test-3 through test-7 also available
make test-all   # Render all test scenes (test-1 through test-7)

Workflow Targets

make run                         # Build and run raytracer
make benchmark                   # Run with timing information
make workflow                    # Full workflow: export → build → render
make export BLEND_FILE=Test1.blend  # Export Blender scene to ASCII
make export-all                  # Export all .blend files

Utility Targets

make convert       # Convert PPM files to PNG
make view-output   # Open output directory (macOS)
make info          # Show build information
make help          # Show all available targets

Examples

Rendering with different features

Disable textures:

./raytracer --scene ASCII/Test1.txt --output Output/result.ppm --disable-textures

High quality render with all features:

./raytracer --scene ASCII/Test5.txt \
  --output Output/result.ppm \
  --resolution 1920 1080 \
  --samples 16 \
  --soft-shadows 16 \
  --glossy-reflection 8 \
  --motion-blur 12 \
  --max-depth 8

Quick preview (low quality):

./raytracer --scene ASCII/Test1.txt \
  --output Output/preview.ppm \
  --resolution 640 480 \
  --samples 4 \
  --max-depth 3

Project Structure

Code/
├── Core/       - Main application, camera, scene, config
├── Math/       - Vector, transform, quaternion utilities
├── Geometry/   - Shape primitives and BVH acceleration
├── IO/         - Image I/O, texture loading, scene parsing
└── Render/     - Raytracing engine
ASCII/          - Scene description files
Blend/          - Blender files and export scripts
Output/         - Rendered images

License

Academic project for computer graphics course.