Bauszat, PabloEisemann, MartinMagnor, MarcusReinhard Koch and Andreas Kolb and Christof Rezk-Salama2014-02-012014-02-012010978-3-905673-79-1https://doi.org/10.2312/PE/VMV/VMV10/227-234Bounding volume hierarchies (BVH) are a commonly used method for speeding up ray tracing. Even though the memory footprint of a BVH is relatively low compared to other acceleration data structures, they still can consume a large amount of memory for complex scenes and exceed the memory bounds of the host system. This can lead to a tremendous performance decrease on the order of several magnitudes. In this paper we present a novel scheme for construction and storage of BVHs that can reduce the memory consumption to less than 1% of a standard BVH. We show that our representation, which uses only 2 bits per node, is the smallest possible representation on a per node basis that does not produce empty space deadlocks. Our data structure, called the Minimal Bounding Volume Hierarchy (MVH) reduces the memory requirements in two important ways: using implicit indexing and preset surface reduction factors. Obviously, this scheme has a non-negligible computational overhead, but this overhead can be compensated to a large degree by shooting larger ray bundles instead of single rays, using a simpler intersection scheme and a two-level representation of the hierarchy. These measure enable interactive ray tracing performance without the necessity to rely on out-of-core techniques that would be inevitable for a standard BVH.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling-Object Hierarchies I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism-Raytracing