Bouatouch, KadiMadani, M.O.Priol, ThierryArnaldi, Bruno2015-10-052015-10-0519871017-4656https://doi.org/10.2312/egtp.19871005This paper describes a new algorithm of space tracing. Scenes are modeled by a CSG tree. Space is subdivided regularly into 3D regions called boxes. With each box is associated a subtree which is the restriction of the whole scene CSG tree to primitives belonging to this box. A 3D grid is used to access boxes.10.2312/egtp.19871005