MiniRT Project

How To Use

1. image build

docker build -t minirt .

2. Host’s X server access rights

xhost +local:docker

3. Run container

docker run -e DISPLAY=$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix minirt

Overview

The MiniRT project is part of the 42 curriculum, where the objective is to implement a ray tracing program. The goal is to render 3D scenes described in a configuration file using a ray tracing algorithm.

This project introduces students to the fundamentals of computer graphics, specifically focusing on the ray tracing technique, which simulates the behavior of light to generate realistic images.

ScreenShot!

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Features

• Render basic geometric shapes such as spheres, planes, and cylinders.
• Support for lighting effects including ambient, diffuse, and specular reflections.
• Multi-light source support (ambient light, point light).
• Parse and render scenes from a configuration file.
• Handle shadows and reflections for enhanced realism.

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Objectives

1. Understand the basics of ray tracing, including ray-object intersections, lighting models, and color rendering.
2. Develop a parser to read and interpret scene configuration files.
3. Build a minimal graphics engine that outputs images to the screen.
4. Gain hands-on experience with vector math, linear algebra, and light behavior in computer graphics.

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Getting Started

Prerequisites

To run MiniRT, ensure you have the following:

• A Unix-based system (Linux or macOS)
• A compiler supporting C99 or later (e.g., GCC or Clang)
• make utility
• A basic understanding of vector mathematics

Installation

1. Clone the repository:

   git clone https://github.com/miniRT-however-we-are-largeRT/miniRT
   cd minirt

2. Build the project:

   make

3. Run the program with a scene file:

   ./minirt scenes/example.rt

Example Scene File

Scene files describe the objects, lights, and camera in the 3D space. Here's an example:

A 0.2 255,255,255
C 0,0,-10 0,0,1 70
L 5,5,-10 1.0 255,255,255

sp 0,0,10 5 255,0,0
pl 0,-5,0 0,1,0 0,255,0
cy 2,0,10 0,1,0 3 10 0,0,255

• A: Ambient light [ratio] [color]
• C: Camera [position] [orientation] [FOV]
• L: Light source [position] [brightness] [color]
• sp: Sphere [position] [diameter] [color]
• pl: Plane [position] [normal vector] [color]
• cy: Cylinder [position] [orientation] [diameter] [height] [color]

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Controls

• ESC or Ctrl + C: Exit the program

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Project Structure

minirt/
├── src/              # Source files
├── include/          # Header files
├── scenes/           # Example scene files
├── lib/              # Libraries (if applicable)
├── Makefile          # Build script
└── README.md         # Project documentation

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Technical Details

Ray Tracing Algorithm

1. Ray Generation: Cast rays from the camera's position through each pixel on the screen.
2. Intersection Testing: Check for intersections between the ray and scene objects (sphere, plane, cylinder).
3. Shading: Compute lighting effects based on light sources and object materials.
4. Pixel Coloring: Determine the final color of each pixel and render the image.

Lighting Model

The project implements the Phong Reflection Model, which includes:

• Ambient Lighting: Uniform light applied to all objects.
• Diffuse Reflection: Light scattered in multiple directions based on surface orientation.
• Specular Reflection: Light reflected in a specific direction, creating highlights.

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Challenges

• Implementing precise mathematical calculations for ray-object intersections.
• Handling edge cases such as objects partially out of the camera's view.
• Optimizing the program for performance while maintaining accurate rendering.

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Roadmap

Potential future improvements:

• Implement multithreading to improve rendering speed.

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Acknowledgments

• The 42 Network for providing this challenging and educational project.
• Resources and tutorials on computer graphics and ray tracing.

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