RAYTRACER:

world + camera

world -> list of hittable objects

viewport ray hittable -> material + location + geometry -> did it hit? screen

notes:

• blurring / antialiasing / focus effect achieved through sampling
• more sampling -> more precise image
• materials are defined by the way they scatter a ray (reflect/refract)

MAIN(): world setup configure camera camera.render()

CAMERA::

CONFIG:

• aspect ratio
• width
• samples per pixel
• max depth (ray scatter recursion)
• vfov
• lookfrom
• lookat
• vup
• defocus angle
• focus dist

RENDER():

• per pixel, color is the average of the sampled rays
• ray(i,j): vector (origin: camera , direction : camera -> pixel [i][j])

ray_color(): rec.mat->scatter() -> material determines attenuation(color %), and further scatter -> random, always scatter --> matte (lambertian) -> random reflection, always scatter -> metal mirror -> add fuzzing on reflection & ensure rays are inside normal hemisphere attenuation is how much the color of the material affects the color of light

shadows:

• if light does a lot of bouncing, color is summed up (absorbed by material) to something close to black

RAYTRACER IS DOING THE REVERSE OF IRL

• IRL: light source -> bounce off objects -> hits eye / camera lens
  • objects absorb light?
• RAY TRACE : camera -> bounce off objects -> light
  • rendered pixels calculated based on how objects interact with light
  • reverse the path!