Lambertian reflectance

A lambertian object obeys Lambert’s cosine law.

Color of a surface is proportional to the cosine of the angle between surface normal and direction to light source

c ∝ cos θ 


  • If a surface points away from light, it should receive no light.
  • Smaller angles -> higher chance that light is reflected back
  • Larger angles -> reflection light gets weaker, it is likely shadowed/masked
  • No dependence on camera angle

References: Tutorials Point