Revelles, J.Aguilera, N.Aguado, J.Lastra, M.Garcia, R.Montes, R.2015-11-122015-11-1220031017-4656https://doi.org/10.2312/egp.20031028We present a spatial representation based on a hierarchical structure using the well-known spatial indexing structure called octree. There are very useful spatial representations for scenes whose objects can be distributed in clusters and here we present a new one. In order to prove its benefits, several results are shown in scenes using a photom tracing algorithm to compute the global illumination based on photon map. These results show that the hierarchy of octrees becomes a good choice to improve the performance when compare to other strategies such as octrees and hierarchy of uniform grids3.