In this paper, we present a single-pass technique to voxelize the interior of watertight 3D models with high resolution grids in realtime during a single rendering pass. Further, we develop a filtering algorithm to build a density estimate that allows the deduction of normals from the voxelized model. This is achieved via a dense packing of information using bitwise arithmetic. We demonstrate the versatility of the method by presenting several applications like translucency effects, CSG operations, interaction for particle simulations, and morphological operations. The speed of our method opens up the road for previously impossible approaches in realtime: 300,000 polygons are voxelized into a grid of one billion voxels at > 90Hz with a recent graphics card. This is the authors' version of the paper. The definitive version has been published in the Proceedings of Graphics Interface 2008. More at http://artis.imag.fr/Publications/2008/ED08a/