Rust Ray Tracer

This is a simple ray tracer written in Rust. It can render scenes with spheres, cubes, planes, and cylinders.

How to Run

To build the project, run the following command:

cargo build

To render a scene, run the following command:

cargo run -- [SCENE_NUMBER] > output.ppm

Where [SCENE_NUMBER] is a number from 1 to 4, corresponding to the four different scenes. If no scene number is provided, scene 1 will be rendered by default.

The output will be a .ppm image file.

Scenes

• Scene 1: A single sphere.
• Scene 2: A flat plane and a cube.
• Scene 3: One of each of all the objects (one cube, one sphere, one cylinder and one flat plane).
• Scene 4: The same as scene 3, but from a different camera position.

How to Add Objects

To add objects to a scene, you need to modify the scene functions in src/main.rs.

Creating a Sphere

To create a sphere, you can use the Sphere::new function:

let sphere = Sphere::new(center, radius, material);

• center: A Vec3 representing the center of the sphere.
• radius: A f64 representing the radius of the sphere.
• material: A Material struct representing the color of the sphere.

Creating a Plane

To create a plane, you can use the Plane::new function:

let plane = Plane::new(point, normal, material);

• point: A Vec3 representing a point on the plane.
• normal: A Vec3 representing the normal of the plane.
• material: A Material struct representing the color of the plane.

Creating a Cube

To create a cube, you can use the Cube::new function:

let cube = Cube::new(min, max, material);

• min: A Vec3 representing the minimum corner of the cube.
• max: A Vec3 representing the maximum corner of the cube.
• material: A Material struct representing the color of the cube.

Creating a Cylinder

To create a cylinder, you can use the Cylinder::new function:

let cylinder = Cylinder::new(center, radius, height, material);

• center: A Vec3 representing the center of the base of the cylinder.
• radius: A f64 representing the radius of the cylinder.
• height: A f64 representing the height of the cylinder.
• material: A Material struct representing the color of the cylinder.

How to Adjust Resolution

The resolution of the output image is determined by the ASPECT_RATIO constant and the image_width variable in the main function in src/main.rs.

const ASPECT_RATIO: f64 = 4.0 / 3.0;

let image_width = 800;
let image_height = (image_width as f64 / ASPECT_RATIO) as i32;

To change the resolution, you can modify image_width and ASPECT_RATIO.

How to Adjust Brightness

The brightness of the objects is determined by the color field of the Material struct. The color is a Vec3 where each component (x, y, z) corresponds to the R, G, and B values of the color, respectively. The values range from 0.0 to 1.0.

To make an object dimmer, you can reduce the values of the color vector. For example, to make a red object dimmer, you can change Vec3::new(1.0, 0.0, 0.0) to Vec3::new(0.5, 0.0, 0.0).

How to Adjust the Light

The position of the light source is defined in the ray_color function in src/main.rs.

let light_pos = Vec3::new(-10.0, 10.0, -10.0);

To change the position of the light, you can modify the values in this Vec3.

How to Move the Camera

The camera is set up in each scene function. To move the camera, you need to modify the arguments passed to the Camera::new function:

let cam = Camera::new(lookfrom, lookat, vup, vfov, aspect_ratio);

• lookfrom: A Vec3 representing the position of the camera.
• lookat: A Vec3 representing the point the camera is looking at.
• vup: A Vec3 representing the "up" direction for the camera.
• vfov: A f64 representing the vertical field of view in degrees.
• aspect_ratio: A f64 representing the aspect ratio of the image.