Abstract: Volumetric representations provide the localization of shapes in space. When such representation is created on the fly from the geometry, it becomes very useful for a wide range of applications (constructive solid geometry (CSG), shape repair, collision detection, etc. Using the advanced functionalities provided by recent GPUs (geometry shaders, 32-bit integer texture format and bitwise operators), we show how to compute a robust scene voxelization and octree construction in a few milliseconds from any hardware-supported rasterizable geometry. Our hierarchical volumetric representation is thus especially well-suited for hierarchical computation of fully dynamic scenes.