1. A computer-implemented method, comprising: receiving an image and associated depth values for each pixel in the image; generating a plurality of copies of the image, each of the copies being associated with a respective number of scattering events; for each of the plurality of copies of the image: applying per-pixel weights to pixels of the copy of the image, thereby producing a weighted copy of the image, wherein the per-pixel weight applied to each pixel represents a probability of an associated light ray experiencing the number of scattering events associated with the copy of the image; applying a respective blur to each of the weighted copies of the image based on the number of scattering events associated with the weighted copy of the image; and summing the blurred weighted copies of the image.