Random emission from point source and diffusing surface -- Algorithm 4.12

These formulae are obtained by using random numbers in the inverse of the equations which describe the distribution of luminous intensity. The symbol R represents a function which gives a different random number on the interval [0,1] each time it is called.

a. Isotropic point source

This gives a scaled random distribution of the angles q and f in general coordinates (algorithm 5.11)

Input

Random numbers, R1, R2

Equation

Source

Tregenza(1)

b. Diffusing surface source

This gives a scaled random distribution of the angles q 'and f' in the local coordinates of the surface.

Input

Random numbers, R1, R2

Equation

Source

Tregenza(1)

References

1. Tregenza P R The Monte Carlo method in lighting calculations Lighting Research and Technology 15 (4) 163-170 (1983)