Under Evolution.

ISOSLIDER: A System for Interactive Exploration of Isosurfaces Jatin Chhugani     Sudhir Vishwanath     Jonathan Cohen     Subodh Kumar    


We present ISOSLIDER, a system for interactive exploration of isosurfaces of a scalar field. Our algorithm focuses on fast update of isosurfaces for interactive display as a user makes small changes to the isovalue of the desired surface. We exploit the coherence of this update. Larger changes are supported as well. The update to the isosurface is made at a correct level of detail so that not too many operations need be performed nor too many triangles need be rendered. ISOSLIDER does not need to retain the entire volume in the main memory and stores most data out of core. The central idea of the ISOSLIDER algorithm is to determine salient isovalues where surface topology changes and pre-encode these changes so as to facilitate fast updates to the triangulation.

Interactive Visualization of Unstructured Grids Using Hierarchical 3D Textures. Joshua Leven     Jason Corso     Subodh Kumar     Jonathan Cohen    


Abstract We present a system for interactively rendering large, unstructured grids. Our approach is to voxelize the grid into a 3D voxel octree, and then to render the data using hierarchical, 3D texture mapping. This approach leverages the current 3D texture mapping PC hardware for the problem of unstructured grid rendering. We specialize the 3D texture octree to the task of rendering unstructured grids through a novel pad and stencil algorithm, which distinguishes between data and non-data voxels. Both the voxelization and rendering processes efficiently manage large, out-ofcore datasets. The system manages cache usage in main memory and texture memory, as well as bandwidths among disk, main memory, and texture memory. It also manages rendering load to achieve interactivity at all times. It maximizes a quality metric for a desired level of interactivity. It has been applied to a number of large data and produces high quality images at interactive, userselectable frame rates using standard PC hardware