Lamb

Format

Lamb // float

The probability of a surface emitting light ray according to Lambertian cosine law. The number of photons emitted in a solid angle $d\mathrm{\Omega }$ is proportional to $\cos (\theta )$, where $\theta$ is the angle between the wave vector of a light ray and the normal vector of the emission surface.

Example

#Lamb
SurfEmit
Shell 1 
1.00000

The probability is 100%.

Math

BSDF	PDF
$\frac{1}{\pi }$	$\frac{\cos \theta }{\pi }$