Abstract: In this paper, we present the first grid-free, out-of-core GPU voxelization method. Our method combines efficient parallel triangle voxelization on GPU with out-of-core technologies in order to allow the processing of scenes with large triangle counts at a high resolution. We directly generate the voxelized data in a sparse voxel octree (SVO) representation, without any intermediate grid structure ("grid-free"). We apply triangle preprocessing and avoid atomic operations, thus leading to an optimized balanced GPU workload and efficient parallel triangle processing. Compared to existing out-of-core CPU approaches, we manage a proper handling of voxel attributes, i.e. all triangle attributes contributing to a voxel are accessible when calculating the voxel attribute. We test and compare our approach to state-of-the-art methods and demonstrate its viability in terms of speed, input triangle count, resolution and output quality.