Final Gathering using Adaptive Multiple Importance Sampling (sap 0079)

Figure 1: Cornell box with a point light source near the ceiling. Left: classic final gathering. Right: our method. The same number of samples is used for both images (512 × 512 pixels, 4 oversamples/pixel, 1024 final gather rays/pixel). The number of iterations for AMIS is 4. The rendering times for left and right are 116.5 seconds and 134.5 seconds, respectively (CPU: Xeon W5590). Our method produces less noise than the classic final gathering with small overhead.