* Features [8/20]

 - [X] Perspective projection
 - [X] Ray-sphere intersection
 - [-] Ray-plane and derived intersections
   - [X] Ray-plane
   - [X] Ray-disk
   - [ ] Ray-triangle
   - [ ] Ray-box
 - [ ] Ray-mesh intersection
 - [ ] Octree mesh
 - [X] Directional lights
 - [X] Point lights
 - [ ] Spotlights
 - [ ] Area lights
   - [ ] Sphere lights
   - [ ] Box/planar lights
   - [ ] Mesh lights
 - [X] Phong shading
 - [X] Specular reflections
 - [X] Transmission
 - [ ] Scene description input files (JSON)
 - [X] Indirect illumination
 - [ ] Russian roulette
 - [ ] Image based lightning
 - [ ] HDR light probes for IBL
 - [ ] Tone mapping
 - [ ] Texture mapping
 - [ ] Photon mapping