Issue No. 06 - November/December (2007 vol. 13)
Charles D. Hansen , IEEE
We describe a system for interactively rendering isosurfaces of tetrahedral finite-element scalar fields using coherent ray tracing techniques on the CPU. By employing state-of-the art methods in polygonal ray tracing, namely aggressive packet/frustum traversal of a bounding volume hierarchy, we can accomodate large and time-varying unstructured data. In conjunction with this efficiency structure, we introduce a novel technique for intersecting ray packets with tetrahedral primitives. Ray tracing is flexible, allowing for dynamic changes in isovalue and time step, visualization of multiple isosurfaces, shadows, and depth-peeling transparency effects. The resulting system offers the intuitive simplicity of isosurfacing, guaranteed-correct visual results, and ultimately a scalable, dynamic and consistently interactive solution for visualizing unstructured volumes.
Ray Tracing, Isosurfaces, Unstructured meshes, Tetrahedra, Scalar Fields, Time-varying data.
I. Wald, H. Friedrich, A. Knoll and C. D. Hansen, "Interactive Isosurface Ray Tracing of Time-Varying Tetrahedral Volumes," in IEEE Transactions on Visualization & Computer Graphics, vol. 13, no. , pp. 1727-1734, 2007.