Ray Tracing

• tuned for specular and transparent objects
• global illumination for specular light
• partly physics-based: geometric optics

Ray tracing tree

  raytrace( ray )
     o find closest intersection
     o cast shadow ray, calculate colour_local
     o colour_reflect = raytrace( reflected_ray )
     o colour_refract = raytrace( refracted_ray )
     o colour = k1*colour_local + k2*colour_reflect
                                + k3*colour_refract
     o return( colour )

Comments

• computationally expensive
  • avoid intersection calculations
    • Voxel grids
    • BSP trees
    • Octrees
    • Bounding volume trees
  • optimize intersection calculations
    • try recent hit first
    • reuse info from numerical methods
• antialiasing
  • supersampling
  • adaptive supersampling
• distributed ray tracing
  • shadow penumbra (several rays per light source, sample source)
  • depth of field (several rays per eye, move eye point)
  • motion blur (several rays per frame, move object)
  • antialiasing (several rays per pixel)