On Jul 30, 2009, at 8:46 AM, Igor Brejc wrote: > Apollinaris Schoell wrote: >> >> On 29 Jul 2009, at 22:05 , Igor Brejc wrote: >> >>> Karl Newman wrote: >>>> >>>> The topology rules are simple--if the ways share a node, then >>>> they are >>>> connected and it is possible to navigate from any of the connected >>>> ways to another (subject to turn restrictions, etc.) The layer >>>> tag is >>>> primarily a hint for renderers for proper display of vertically >>>> separated features. If the data is otherwise, then it is an error >>>> and >>>> should be corrected. >>>> >>> Then how do you handle double-decker bridges? >>> (http://en.wikipedia.org/wiki/Bridge#Double-decker_bridge) >>> >> >> 2 ways with different layer number >> > I was asking more about the "sharing/not sharing nodes" stuff > between those two ways >
can't think of a case where they could share a node. only if we start to map an elevator between the 2 ways. but then osm needs to extend to a 3d model. mapping 3d with elevation tag might be to simplistic.... at the end of the bridge when the 2 ways can merge into one again then topology rule applies as outlined by Karl > Igor > > > -- > http://igorbrejc.net > _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev