On Mon, Aug 30, 2010 at 11:18 PM, Richard Welty <[email protected]> wrote: > i'd lean towards site relations being useful because i think that > the computational complexity of doing lots of polygon intersections > is being underestimated. yes, for small bounding boxes it's ok, > but consider if you needed to do it on a larger scale, it'd make > certain tasks completely unreasonable (i'm not sure what those > tasks might be yet, haven't thought about it.)
Yep. Polygon collisions can also be accidental, like when two objects from slightly different sources (say one gps, one aerial imagery) are near each other. A relation is a very explicit statement. Other generic relation types that would be very useful: - "these objects are mutually accessible by foot" (to avoid having to invent artificial foot paths in order to get good routing) - "these objects express the same thing as that object but in more detail" (eg, one line representing a pair or more of train lines) - "these objects are one" (like a very generic multipolygon, could also work to form "multiways") Steve _______________________________________________ Tagging mailing list [email protected] http://lists.openstreetmap.org/listinfo/tagging
