Issue No. 06 - November/December (2009 vol. 15)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TVCG.2009.204
Aaron Knoll , University of Kaiserslautern
Younis Hijazi , University of Strasbourg
Rolf Westerteiger , University of Kaiserslautern
Mathias Schott , SCI Institute, University of Utah
Charles Hansen , SCI Institute, University of Utah
Hans Hagen , University of Kaiserslautern
Direct volume rendering and isosurfacing are ubiquitous rendering techniques in scientific visualization, commonly employed in imaging 3D data from simulation and scan sources. Conventionally, these methods have been treated as separate modalities, necessitating different sampling strategies and rendering algorithms. In reality, an isosurface is a special case of a transfer function, namely a Dirac impulse at a given isovalue. However, ar tifact-free rendering of discrete isosurfaces in a volume rendering framework is an elusive goal, requiring either infinite sampling or smoothing of the transfer function. While preintegration approaches solve the most obvious deficiencies in handling shar p transfer functions, ar tifacts can still result, limiting classification. In this paper, we introduce a method for rendering such features by explicitly solving for isovalues within the volume rendering integral. In addition, we present a sampling strategy inspired by ray differentials that automatically matches the frequency of the image plane, resulting in fewer ar tifacts near the eye and better overall performance. These techniques exhibit clear advantages over standard uniform ray casting with and without preintegration, and allow for high-quality interactive volume rendering with shar p C0 transfer functions.
direct volume rendering, isosurface, ray casting, ray differentials, sampling, transfer function, preintegration, view dependent
A. Knoll, C. Hansen, H. Hagen, R. Westerteiger, Y. Hijazi and M. Schott, "Volume Ray Casting with Peak Finding and Differential Sampling," in IEEE Transactions on Visualization & Computer Graphics, vol. 15, no. , pp. 1571-1578, 2009.