Lecture 13: Global Illumination & Path Tracing (38)
noah-ku
The transport operator is similar to the reflection operator, but instead of taking in incoming radiance and outputting outgoing radiance, it does the opposite. If you know the outgoing light of all surfaces, the radiance will be deposited at the end of the next intersection point. Given these two operators, we can get some circularity between the light that bounces between objects.
GarciaEricS
Is it not the case that T(L_i) = L_o? It seems like it should be symmetric, because the transport operator is basically saying that any light that enters one point in one direction is the same light that exits the first contact point in the opposite direction. Should it not be the case that any light that exits one point in one direction is the same light that enters the first contact point in the opposite direction? It may not be helpful, but am I wrong in thinking that we should have some symmetry here?
The transport operator is similar to the reflection operator, but instead of taking in incoming radiance and outputting outgoing radiance, it does the opposite. If you know the outgoing light of all surfaces, the radiance will be deposited at the end of the next intersection point. Given these two operators, we can get some circularity between the light that bounces between objects.
Is it not the case that T(L_i) = L_o? It seems like it should be symmetric, because the transport operator is basically saying that any light that enters one point in one direction is the same light that exits the first contact point in the opposite direction. Should it not be the case that any light that exits one point in one direction is the same light that enters the first contact point in the opposite direction? It may not be helpful, but am I wrong in thinking that we should have some symmetry here?