Direct Mesh: a Multiresolution Approach to Terrain Visualisation
Speaker: Kevin Xu, ITEE
When: 2003-08-07 14:00:00
Venue: 78-420
Host: Ralf Muhlberger
Abstract:Terrain can be approximated by a triangular mesh consisting millions
of 3D points. Multiresolution triangular mesh (MTM) structures are
designed to support applications that require terrain data of
variable level of details (LOD). Typically, an MTM adopts a tree
structure where a parent node represents a lower-resolution
approximation of its descendants. Given a region of interest (ROI)
and a LOD, the process of retrieving the required terrain data from
the database is to traverse the MTM tree from the root to reach all
the nodes satisfying the ROI and LOD conditions. This process, while
being commonly used for multiresolution terrain visualisation, is
inefficient as the process of fetching data following the tree
structure means either a large number of sequential I/O operations
or fetching a large amount of extra data. Various spatial indexes
have been proposed in the past to address this problem; however,
level-by-level tree traversal remains a common pattern in order to
obtain topological information among the retrieved terrain data. In
this paper, a new MTM data structure called direct mesh is
proposed. We demonstrate that with direct meshes a minimum amount of
data can be retrieved directly from the database. Comparing with
existing MTM indexing methods, a significant performance improvement
has been observed for real-life terrain data.
Biography:(biography unavailable)
Type: DKE Seminar
Contact:Ralf Muhlberger, seminar host (ralf@itee.uq.edu.au)
or Guido Governatori (ITEE seminar co-ordinator)
(guido@itee.uq.edu.au)