I think this is very interesting as well. Why store "TIN structure in a database"?? On the surface, I think that it is reasonable to say, for the same reason that you store anything other than strings and floats in a database? The answer is so that you can have robust access to query logic, independent of a specific file system, integrated with SQL, and in the case of TIN's, potentially exploitable via geo-processing queries. This would offer a very powerful advantage.
In many cases, the TIN can be a substitute for raster data, a highly efficient one (not in all cases of course). For terrain modelers, this could be fantastic. $0.02, r.b. Robert W. Burgholzer Surface Water Modeler Office of Water Supply and Planning Virginia Department of Environmental Quality [EMAIL PROTECTED] 804-698-4405 Open Source Modeling Tools: http://sourceforge.net/projects/npsource/ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kevin Neufeld Sent: Monday, September 22, 2008 4:27 PM To: PostGIS Users Discussion Subject: Re: [postgis-users] TIN support yes or no? Courtin Olivier wrote: > > On Sep 20, 2008, at 6:44 PM, Paul Ramsey wrote: > > Paul, > >> and I have a hard time reconciling that to the >> real use-case needs of TIN-in-database (really large, region-spanning, >> billion-face TINs). > > Well, why want to store such kind of TIN structure into a database ? :) So one doesn't have to recompute a surface repeatedly. I'm currently working on a project where I need to build up a surface model on a provincial scale, computing the overlay of streams and other hydrographic features. Since I only have the resources to build a small portion of the entire surface at a time, I'm forced to generate a very small surface, and with a large buffered area, slowly pan over the entire province, thus generating the TIN in the overlapping buffered areas repeatedly (estimated to take a total time 1200 CPU hours). Having a reusable TIN stored in the database is rather appealing. This is of particular interest: streaming TIN generation - nice! http://www.cs.unc.edu/~isenburg/papers/ilsst-tin2dem-06.pdf Cheers, Kevin _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
