The gathered intensity can be estimated by generating a set of samples in the unit circle, lifting these onto the hemisphere, and then seeing what was the radiosity of the element that a ray incoming in that direction would have originated on. The estimate for the total gathered intensity is then just the average of the radiosities discovered by each ray. Similarly, in the power formulation, power can be distributed by generating a set of rays from the radiating element in the same way, and spreading the power to be distributed equally between each element a ray hits.
The gathered intensity can be estimated by generating a set of samples in the unit circle lifting these onto the hemisphere and then seeing what was the radiosity of the element that a ray incoming in that direction would have originated on The estimate for the total gathered intensity is then just the average of the radiosities discovered by each ray Similarly in the power formulation power can be distributed by generating a set of rays from the radiating element in the same way and spreading the power to be distributed equally between each element a ray hits