What's the background in this pot?

If integral of fr cos(theta) has to be less than or equal to 1, why can this fr give an infinite value?

Is the integral of Dirac delta over all real numbers equal to 1?

How do we think about BRDF as distributions? Is there a simple example?

What's the background in this pot?

If integral of fr cos(theta) has to be less than or equal to 1, why can this fr give an infinite value?

Is the integral of Dirac delta over all real numbers equal to 1?

How do we think about BRDF as distributions? Is there a simple example?