TY - CHAP A1 - Lier, Alexander A1 - Martinek, Magdalena A1 - Stamminger, Marc A1 - Selgrad, Kai T1 - A High-Resolution Compression Scheme for Ray Tracing Subdivision Surfaces with Displacement T2 - Proceedings of the ACM on Computer Graphics and Interactive Techniques N2 - Subdivision surfaces, especially with displacement, are one of the key modeling primitives used in high-quality rendering environments, such as, e.g., movie production. While their use easily maps to rasterization-based frameworks, they pose a significant challenge for ray tracing environments. This is due to the fact that incoherent access patterns require storing or caching fully tessellated and displaced meshes for efficient intersection computations. In this paper we use a two-tier hierarchy built on a scene's patches. It relies on compressed and quantized bounding volumes on the second tier to reduce the size of the BVH itself. Based on this acceleration structure, we propose a quantized, compact approximation for leaf nodes while being faithful to the underlying patch-geometry. We build on recent advances and present a system that shows competitive performance regarding run-time speed, which is close to full-resolution pre-tessellation methods as well as to previous compression approaches. Ultimately, we provide strong compression of up to a factor of 5: 1 compared to state-of-the-art methods while maintaining high geometrical fidelity surpassing similarly compact approximations and getting close to uncompressed geometry. KW - Displacement Mapping KW - omputing methodologies KW - Parametric curve and surface models KW - Production Rendering KW - ray tracing KW - Subdivision Surfaces Y1 - 2018 U6 - https://doi.org/10.1145/3233308 VL - 1 IS - 2 SP - 1 EP - 17 PB - The Association for Computers in Mathematics and Science Teaching ER - TY - JOUR A1 - Selgrad, Kai A1 - Lier, Alexander A1 - Martinek, Magdalena A1 - Buchenau, Christoph A1 - Guthe, Michael A1 - Kranz, Franziska A1 - Schäfer, Henry A1 - Stamminger, Marc T1 - A Compressed Representation for Ray Tracing Parametric Surfaces JF - ACM Transactions on Graphics N2 - Parametric surfaces are an essential modeling tool in computer aided design and movie production. Even though their use is well established in industry, generating ray-traced images adds significant cost in time and memory consumption. Ray tracing such surfaces is usually accomplished by subdividing the surfaces on-the-fly, or by conversion to a polygonal representation. However, on-the-fly subdivision is computationally very expensive, whereas polygonal meshes require large amounts of memory. This is a particular problem for parametric surfaces with displacement, where very fine tessellation is required to faithfully represent the shape. Hence, memory restrictions are the major challenge in production rendering. In this paper, we present a novel solution to this problem. We propose a compression scheme for a-priori Bounding Volume Hierarchies (BVHs) on parametric patches, that reduces the data required for the hierarchy by a factor of up to 48. We further propose an approximate evaluation method that does not require leaf geometry, yielding an overall reduction of memory consumption by a factor of 60 over regular BVHs on indexed face sets and by a factor of 16 over established state-of-the-art compression schemes. Alternatively, our compression can simply be applied to a standard BVH while keeping the leaf geometry, resulting in a compression rate of up to 2:1 over current methods. Although decompression generates additional costs during traversal, we can manage very complex scenes even on the memory restrictive GPU at competitive render times. KW - Production Rendering KW - Subdivision Surfaces KW - Displacement Mapping KW - Ray Tracing Y1 - 2016 U6 - https://doi.org/10.1145/2953877 VL - 36 IS - 1 SP - 1 EP - 13 PB - ACM CY - New York, NY, USA ER -