For example, if a ray casting program is not very selective when choosing triangles to test, a lower percentage of rays will pass the u and v tests. The orientation of the rays with respect to the data impacts the percentage of rays eliminated by back face culling. In the case of these statistics, the viewing rays do not have a uniform directional distribution. While this breakdown cannot account for every cycle of computation, it provides a reasonably complete characterization of the work to be done. It is presumed that if efficiency were of primary concern, collateral loading and storing operations could be minimized.
Division can take from four to eight times as long as the other operations.
To account for this disparity, divisions are counted here as four computational units, while the other operations are counted as one computational unit. The following four tables present computational totals for our method and Badouel's method, both with noncoplanar test and back face culling. Each table lists the number of operations of each type in each section of code. These operation counts are then scaled by each code section's execution percentages, and then summed to find an average total operation count. The average total operation values demonstrate that the presented method is computationally equivalent to Badouel's method when back facing triangles are not culled.