Fakultät Informatik

Vector-to-Closest-Point Octree for Surface Ray-Casting

 Ismail Demir, Rüdiger Westermann

Computer Graphics and Visualization Group, Technische Universität München, Germany


GPU voxel-based surface ray-casting has positioned as an interesting alternative to rasterization-based rendering approaches, because it allows using many processing units simultaneously, can effectively exploit thread level parallelism, and enables fine-granularity occlusion culling on the pixel level. Yet voxel-based techniques face the problem that an extremely high resolution is necessary to avoid block artifacts at high zoom levels. In this work, we propose a novel improvement of voxel-based ray-casting to overcome this limitation. By using a hierarchical Vector-to-Closest-Point (VCP) representation, we can inherit the advantages of a voxel-based approach at a much smoother approximation of the surface. We demonstrate that, although the VCP grid consumes more memory per cell, it requires less memory overall, because it builds upon a significantly shallower tree hierarchy. In a number of examples we demonstrate the use of our approach for high-quality rendering of high resolution surface models.


This work was supported by the European Union under the ERC Advanced Grant 291372 - SaferVis - Uncertainty Visualization for Reliable Data Discovery.

Associated publications

Vector-to-Closest-Point Octree for Surface Ray-Casting
I. Demir, R. Westermann Proceedings of Vision, Modeling and Visualization 2015 (accepted for publication) [Download] [Bibtex]



- In collaboration with partners from industry, we have a number of thesis topics available in the area of point-based rendering, geo-localization using public data, scene fusion from different viewpoints. If you are interested, please contact  westermann(at)tum.de


- Game Devel. Lab Practical for SS'18: kick off meeting on April 3rd,  details here. No matching system sign upneeded!


- One PhD position on   Turbulence Visualization is available at the Computer Graphics & Visualization group.