DEM data in a database

["Michael Bean" <MBEAN@us.oracle.com>]

Title:

Since everyone is talking DEM 
this week, I thought I would make a plug for the stuff I've been working 
on.  Okay I work for a database company so you guessed it, storing grid 
data in a database.  One advantage of storing the grid data in a database 
is that generating terrains for arbitrary regions is a snap.  I also 
generate color data for ElevationGrids and IndexedLineSets by interpolating 
the height data against a color table associated with key heights.  
Lower resolution terrains can be generated from the sample point data.  
An importer was written to import USGS DEM 7.5 Minute files (30m spacing) 
and multiple files can be loaded in to the same layer if they belong 
to the same UTM zone.  A rather crude example which uses this approach 
can be viewed at:
 
http://ws10.olab.com/sample/livevrml/LVGridDEMViewer/content/index.html
 
All the magic occurs in Java code 
run in an Oracle Internet Application Server using JDBC to access an 
Oracle database.  This site has been a bit flaky lately so let me know 
me know if you have problems using the demo.  The idea is to use the 
terrain with VRML representations of objects whose locations are maintained 
in a relational database.  Our team is also working on an application 
framework for developing VRML visualization applications on an Oracle 
Internet Application Server.
 
Mike Bean
VRML Technologies
Internet Application Servers Division
650-506-3687