This project reverses the ray directions and sends rays from the sensor to the light. The scene now importance samples the light instead of the pinhole. The adjoint image below contains some noisy artifacts from a bug due to energies that are too high. However, these artifacts become less noticeable as the image converges. Unfortunately, I didn't have time to let the adjoint image completely. I did notice that the regions occluded from the light converge much faster using the adjoint approach. The images were tone mapped using clamping and gamma corrected using the same parameters, except running time which was not as long for the adjoint image.
