Efficient rendering of strong secondary lighting in photon mapping algorithm

In this paper we propose an efficient algorithm for handling strong secondary light sources within the photon mapping framework. We introduce an additional photon map as an implicit representation of such light sources. At the rendering stage this map is used for the explicit sampling of strong indirect lighting in a similar way as it is usually performed for primary light sources. Our technique works fully automatically, improves the computation performance, and leads to a better image quality than traditional rendering approaches