miniRT

A simple ray tracer built in C using the Phong lighting model. This project renders 3D scenes defined in .rt files, supporting spheres, planes, cylinders, and cones with configurable lighting and textures.

Gallery

Features

• Ray tracing with Phong lighting model (ambient, diffuse, and specular components)
• Multi-threaded rendering for improved performance
• Supported objects:
  • Spheres (sp)
  • Planes (pl)
  • Cylinders (cy)
  • Cones (co)
• Multiple light sources with configurable brightness and color
• Checkerboard texture pattern
• Configurable camera position, orientation, and field of view

Requirements

• Linux with X11
• GCC compiler
• Make
• X11 development libraries (libx11-dev, libxext-dev)

Install dependencies (Debian/Ubuntu)

sudo apt-get install libx11-dev libxext-dev

Install dependencies (Fedora)

sudo dnf install libX11-devel libXext-devel

Building

make

To rebuild from scratch:

make re

To build with debug symbols and sanitizers:

make debug

Usage

./miniRT -s <scene_file.rt>
./miniRT --scene=<scene_file.rt>

Options

Option	Description
-s, --scene=FILE	Scene file to render (.rt format)
-h, --help	Display help message
-V, --version	Display version information

Controls

• ESC or Q - Close the window and exit

Example

./miniRT -s scenes/room.rt

Scene File Format (.rt)

Scene files use a simple text format where each line defines an element.

Ambient Light (A)

A <ratio> <R,G,B>

• ratio: Ambient lighting ratio (0.0 to 1.0)
• R,G,B: Color in RGB format (0-255 each)

Example: A 0.2 255,255,255

Camera (C)

C <x,y,z> <vx,vy,vz> <fov>

• x,y,z: Camera position
• vx,vy,vz: Normalized orientation vector (-1.0 to 1.0)
• fov: Field of view in degrees (0 to 180)

Example: C 0,0,20 0,0,-1 70

Light (L)

L <x,y,z> <brightness> [R,G,B]

• x,y,z: Light position
• brightness: Light brightness ratio (0.0 to 1.0)
• R,G,B: (Optional) Light color

Example: L -40,50,0 0.6 255,255,255

Sphere (sp)

sp <x,y,z> <diameter> <R,G,B> [specular] [texture]

• x,y,z: Center position
• diameter: Sphere diameter
• R,G,B: Color
• specular: (Optional) Specular coefficient
• texture: (Optional) c for checkerboard

Example: sp 0,0,20 12.6 10,0,255 0.5 c

Plane (pl)

pl <x,y,z> <nx,ny,nz> <R,G,B> [specular] [texture]

• x,y,z: Point on the plane
• nx,ny,nz: Normal vector (-1.0 to 1.0)
• R,G,B: Color
• specular: (Optional) Specular coefficient
• texture: (Optional) c for checkerboard

Example: pl 0,-10,0 0,1,0 0,255,0 0

Cylinder (cy)

cy <x,y,z> <nx,ny,nz> <diameter> <height> <R,G,B> [specular] [texture]

• x,y,z: Center of the base
• nx,ny,nz: Axis direction (-1.0 to 1.0)
• diameter: Cylinder diameter
• height: Cylinder height
• R,G,B: Color

Example: cy 50,0,20.6 0,0,1 14.2 21.42 10,0,255 0.5

Cone (co)

co <x,y,z> <nx,ny,nz> <diameter> <height> <R,G,B> [specular] [texture]

• x,y,z: Apex position
• nx,ny,nz: Axis direction (-1.0 to 1.0)
• diameter: Base diameter
• height: Cone height
• R,G,B: Color

Example: co 0,0,0 0,1,0 10 15 255,128,0 0.8

Sample Scenes

The scenes/ directory contains example scene files:

• room.rt - Indoor scene with multiple objects
• multispheres.rt - Multiple spheres demonstration
• cylindercaps.rt - Cylinder with caps
• scene.rt - Basic scene

Project Structure

.
├── incs/               # Header files
├── minilibx/           # MiniLibX graphics library
├── scenes/             # Example scene files
├── srcs/               # Source files
│   ├── parsing/        # Scene file parsing
│   └── render/         # Ray tracing and rendering
├── Makefile
└── README.md

References

Ray Tracing

• Ray Tracing in One Weekend - Excellent introduction to ray tracing
• Scratchapixel - Comprehensive computer graphics tutorials
• Ray Tracing (Wikipedia)

Lighting

• Phong Reflection Model - The lighting model used in this project
• Phong Shading (Learn OpenGL)

Ray-Object Intersections

• Ray-Sphere Intersection
• Ray-Plane Intersection
• Ray-Cylinder Intersection
• Quadric Surfaces - Mathematical basis for cones and cylinders

Books

• "Fundamentals of Computer Graphics" by Peter Shirley
• "Physically Based Rendering: From Theory to Implementation" by Pharr, Jakob & Humphreys

Authors

• sdummett
• etran

This project was developed as part of the 42 school curriculum.