Do all 'hits' have constant energy? If not, why do we only care about the number of hits?
Can radiant energy vary across the landscape of a scene?
Do hits of rays with different angles and different length all carry the constant energy?
Is radiant energy measured across an entire scene? Or by some smaller size like across an object
But how can we measure the number of hits in the scene?
This seems counterintuitive to me: I thought that the amount of energy in the scene should be fixed. How come the amount of energy can increase every time a photon hits something. Aren't we "double-counting" the energy associated with a photon?
Does the energy decrease after every hit/ how do we keep track of it if it does?
Is there a rate of decreasing energy we will have to measure given a photon of light or do we assume light is infinitely fast (so just for an instant) or do we assume it lasts forever?