So, John, when you say ""ST_SimplifyPreserveTopology" that prevents splinters and invalid polygons being formed by the D-P process" does that mean it solves the problem you are talking about with D-P? Or does this still exist? If it still exists I guess I don't understand how you are suggesting it be solved.
On Wed, Dec 10, 2008 at 1:32 PM, maps.huge.info [Maps API Guru] < [EMAIL PROTECTED]> wrote: > > Mike, > > The problem with D-P and common borders is due to the direction the > algorithm takes when simplifying the border. For neighboring polygons, > the algorithm will go in opposite directions for every common line. > You can see this yourself by just tracing the border with your finger > around one polygon, then do the same with its neighbor. D-P will > calculate different simplification results depending on where it > starts, so slivers and other issues are inevitable. The only way > around this, and it can be done, is to determine common borders, break > them into lines, simplify them one at a time, reassemble the polygons, > check for invalid results (crossing lines, etc.), fix those and you're > done. Sounds easy, doesn't it? > > While it does sound daunting, if you start with the base geometry, the > Tiger edges shapefile, and simplify that before building the edges > into larger shapes, the results are easier to deal with. > > -John Coryat > > http://maps.huge.info > > http://www.usnaviguide.com > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
