title: Selective refinement queries for volume visualization of unstructured tetrahedral meshes.
abstract: In this paper, we address the problem of the efficient visualization of large irregular volume data sets by exploiting a multiresolution model based on tetrahedral meshes. Multiresolution models, also called Level-Of-Detail (LOD) models, allow encoding the whole data set at a virtually continuous range of different resolutions. We have identified a set of queries for extracting meshes at variable resolution from a multiresolution model, based on field values, domain location, or opacity of the transfer function. Such queries allow trading off between resolution and speed in visualization. We define a new compact data structure for encoding a multiresolution tetrahedral mesh built through edge collapses to support selective refinement efficiently and show that such a structure has a storage cost from 3 to 5.5 times lower than standard data structures used for tetrahedral meshes. The data structures and variable resolution queries have been implemented together with state-of-the art visualization techniques in a system for the interactive visualization of three-dimensional scalar fields defined on tetrahedral meshes. Experimental results show that selective refinement queries can support interactive visualization of large data sets.
authors.affiliation: Istituto di Scienza e Tecnologie dell'Informazione, Consiglio Nazionale delle Ricerche, Via G. Moruzzi, 1, 56124 Pisa, Italy. cignoni@iei.pi.cnr.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Cignoni
authors.forename: Leila
authors.initials: L
authors.lastname: De Floriani
authors.forename: Paola
authors.initials: P
authors.lastname: Magillo
authors.forename: Enrico
authors.initials: E
authors.lastname: Puppo
authors.forename: Roberto
authors.initials: R
authors.lastname: Scopigno
mesh_terms: D000465:Algorithms; D003196:Computer Graphics; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D009862:Online Systems; D010363:Pattern Recognition, Automated; D012815:Signal Processing, Computer-Assisted; D014584:User-Computer Interface