Patent ID: 8279220

Claim:
A method for estimating the light transported between a first point A and a second point B, the method comprising: selecting a plurality of first sub-paths extending from a first point A; selecting a plurality of second sub-paths extending from a second point B; constructing, utilizing a processor, a plurality of transport paths, wherein each one of the plurality of the first sub-paths is coupled to a respective one of the plurality of the second sub-paths to form one transport path, and wherein each transport path comprises one first sub-path and one second sub-path; sampling two or more of the plurality of the transport paths to obtain a plurality of sampled transport paths; and calculating a light transport value for each of the plurality of sampled transport paths to estimate light transported between the first point A and the second point B; wherein constructing the plurality of transport paths comprises: constructing a light transport matrix, wherein the plurality of first sub-paths defines respective column indices and the plurality of second sub-paths defines respective row indices, the light transport matrix including an entry G ij defined by a respective column i and a respective row j, whereby the entry G ij comprises a light transport value which describes light transported between the points A and B via a light transport path comprising a combination of a first sub-path corresponding to the column i, and a second sub-path corresponding to the row j; wherein constructing the light transport matrix comprises: sorting the plurality of first sub-paths into a plurality of different first sub-path groups, each of the first sub-path groups comprising first sub-paths having a same first path length, and sorting the plurality of second sub-paths into a plurality of different second sub-path groups, each of the second sub-path groups comprising second sub-paths having a same second path length; wherein one of the first sub-path groups and one of the second sub-path groups collectively form a sub-matrix within the light transport matrix, each sub-matrix comprising a plurality of column indices and a plurality of row indices, wherein each column index corresponds to a respective first sub-path, and each row index corresponds to a respective second sub-path; wherein a plurality of sub-matrices form the light transport matrix; wherein one or more column indices of one or more of the plurality of sub-matrices is ordered, comprising: selecting one of the plurality of sub-matrices, the selected sub-matrix comprising a plurality of first sub-paths and a plurality of second sub-paths, selecting a first column index for the selected sub-matrix, and selecting, from among a predefined number of remaining column indices, a second column index for the selected sub-matrix based upon the first selected column index.