Kotlin Ray Tracer

Learning Kotlin by reading through The Ray Tracer Challenge https://pragprog.com/book/jbtracer/the-ray-tracer-challenge and implementing the concepts in the book. This repo is to track my progress.

Features

This ray tracer includes various shapes and is able to handle opaque, transparent and reflective surfaces

Object types

1. Sphere
2. Plane
3. Cube
4. Cylinder
5. Cone
6. Triangle
7. CSG Operations
   1. Union
   2. Intersection
   3. Difference

TODO

• Add area light
  • One idea is to add it as a type of material and then any object can become a light source
• Add a CompositeColor class
  • Convert current Color class to an Interface and add a SingleColor class?
  • CompositeColor should store multiple Colors (and perhaps the Points that they came from?) and return the average of the colors stored
  • See if this class can inherit from or implement Deferred or Deferred
• Change inShadow from a boolean to a float of brightness between 0 and 1
  • The brightness would be calculated by casting multiple rays from a point to different parts of the light source surface and return hits/rays cast
• Add aperture (focal length already exists) and cast multiple rays from the point of the camera starting in a circle the radius of the aperture and all aiming at the focal point
  • The number of rays to cast should be some function of the aperture size squared. e.g. size of 0 = 1 ray. size of 0.2 = 4 rays, size of 0.4 = 16 rays
• Add a roughness parameter to materials
  • The roughness should be an integer that dictates the number of ray to re-cast once a ray from the camera hits a point. The re-cast rays should be cast in random directions that are focused around the direction of a perfect reflection ray
  • This will give the image a sense of ambient color (maybe ignore the ambient parameter when roughness is used?)
• Add more sophisticated post-processing for "shadows" of transparent materials
  • For each light source and each transparent object, cast rays at the transparent object and trace the ray until it hits a non-transparent point.
  • When the point is hit, find all CompositeColors that correspond to the point and add the light hit to the list
  • Some light might be lost along the way if the material passed through is not 100% transparent

Example