Julia Ray-Tracer

A simple ray tracer implemented in Julia.

Ray-Tracer "Framework"

Scene objects

Scene objects are structs that subtypes from SceneObject. Scene objects (Object) must have the following functions:

"Intersection with the object's surface"
function intersection(ray::Ray, object::Object)::Union{Miss, Intersection}
    ...
end

"Interaction of the ray to the surface"
function interact(ray::Ray, hit::Intersection{Object}, scene::Scene)::RGB
    ...
end

Interactions with the rest of the scene are handled in interact. Some interactions that the object could have are:

• Refraction
• Reflection
• Ray teleportation
• Specular highlights

Some interactions may require another another ray trace. So the function ray_trace is available to simulate another ray.

Base objects

TODO

Important types

Ray

A ray has an origin and a direction. This values are used to calculate the intersection with objects. The directions also might be used to calculate special properties with the materials of the intercepted objects.

Miss and Intersection

Miss and intersections are the result of the intersection function.

A Miss is a singleton, a struct without attributes.

An Intersection contains the information of a intersection: the intercepted object, the distance, and the intercepted point.

Camera

The camera that will render the scene. The current attributes are:

• Position: A point where the image will start
• Direction: Where the camera is looking, relative to it's position
• Focal length: Distance from the screen to the "eye"
• Roll: Rotation in the direction axis
• Size: Image size in the scene
• Resolution: Image output size
• Down direction: Where down is for the camera (usually [0, 1, 0])

Scene

TODO

Important functions

Render

render(scene::Scene, camera::Camera; max_steps=10)::Array{RGB, 2}

Renders the scene with the camera.

Ray step

ray_trace(ray::Ray, scene::Scene, step::Int)::RGB

Calculates the intersection with the closes object and calls interact with the intercepted object.

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Special Thanks

This code is posible thanks to:

• http://math.hws.edu/graphicsbook/c4/s1.html
• https://github.com/avik-pal/RayTracer.jl