42_miniRT

My first RayTracer with miniLibX.

This project is about creating a Ray Tracer in C. A Ray Tracer is a program that accurately simulates the illumination of objects by light sources by tracing how the light rays interact with the objects and the camera (eye).

Project Goals and rules

The program takes in a ".rt" file as a parameter, that will set how the scene will look like. The scene contains:

Camera

* Identifier: C
* Position: x, y, z
* Orientation vector: x, y, z (normalized)
* FOV: from 0 to 180 degrees

Ambient Light

* Identifier: A
* Ambient lighting ratio in range [0.0,1.0]: 0.2
* R,G,B colors in range [0-255]: 255, 255, 255

Light Source

* Identifier: L
* x,y,z coordinates of the light point: -40.0,50.0,0.0
* The light brightness ratio in range [0.0,1.0]: 0.6
* (unused in mandatory part)R,G,B colors in range [0-255]: 10, 0, 255

Objects

Sphere

* Identifier: sp
* x,y,z coordinates of the sphere center: 0.0,0.0,20.6
* The sphere diameter: 12.6
* R,G,B colors in range [0-255]: 10, 0, 255

Plane

* Identifier: pl
* x,y,z coordinates of a point in the plane: 0.0,0.0,-10.0
* 3d normalized normal vector. In range [-1,1] for each x,y,z axis: 0.0,1.0,0.0
* R,G,B colors in range [0-255]: 0,0,225

Cylinder

* identifier: cy
* x,y,z coordinates of the center of the cylinder: 50.0,0.0,20.6
* 3d normalized vector of axis of cylinder. In range [-1,1] for each x,y,z axis:
0.0,0.0,1.0
* The cylinder diameter: 14.2
* The cylinder height: 21.42
* R,G,B colors in range [0,255]: 10, 0, 255

Example .rt file for scene

A 0.2 255,255,255

C -50,0,20 0,0,1 70
L -40,0,30 0.7 255,255,255

pl 0,0,0 0,1.0,0 255,0,225
sp 0,0,20 20 255,0,0
cy 50.0,0.0,20.6 0,0,1.0 14.2 21.42 10,0,255

Documentation

Overall program structure

Tasks

• Minilibx - Set up functional window management: opening, free, closing, ESC
• Parser - Analyze the file and create structures for each object and light.
• Utilities
  • Functions to calculate vector sum, multiplication, calculate the simetric of a vetor, magnitude and to normalize
  • Function - dot product
  • Matrizes - criar funcoes: invert, transpose, multiply
  • Matrizes - funcoes transformacao de objetos: translation and rotation
  • Create ray structure - vector and starting point (camera).
  • Function to calculate the first intersection between a ray and an object.
  • Functions to calculate the vectors associated to an intersection (normal, eye, light and reflection)
  • Diffuse_light = object_color * light_intensity * dot_product(normal_vector, light_vector)
  • Function color_pixel_hit = diffuse + ambient light
  • Shadows - Implement shadowing

References

• jburlama: https://github.com/Jburlama/miniRT?tab=readme-ov-file
• Ray Tracing by Joao Manuel Brisson Lopes: https://disciplinas.ist.utl.pt/leic-cg/textos/livro/Ray%20Tracing.pdf
• The Raytracer Challenge: https://www.bharatchan.com/images/uploads/g/173159035800090.pdf
• Shader Toy: https://www.shadertoy.com/view/tl23Rm
• Ray Tracing in one week: https://raytracing.github.io/books/RayTracingInOneWeekend.html#thevec3class/colorutilityfunctions

Installing and Using

To download, clone the repository into your device and navigate inside using cd minirt, then typing make to compile all the functions and generate the executable push_swap, which you can run as follows:

./minirt path_to_.rt_file

where the path_to_.rt_file is the path to a file with a .rt extension that contains the scene parameters shown above.

Disclaimer

At 42 School our projects have to adhere to the 42 Norm of coding standards and good practices. These include:

• Maximum 25 lines per function and 5 functions per file;
• No variable declarations and assignments in the same line;
• Forbiden structures: for, switch, goto and case;
• No more than 5 variables per function.

All of my projects strictly adhere to this Norm, that promotes code simplicity and readability.