[OSM-talk] Key:layer update

[Richard Z.]

On Sun, Mar 09, 2014 at 11:47:32AM +0100, Martin Koppenhoefer wrote:
> 
> 
> > Am 09/mar/2014 um 11:30 schrieb "Richard Z." <ricoz.osm at gmail.com>:
> > 
> > * the vertical ordering established by the layer values is valid exactly only 
> >  in the point where the ways cross or objects overlap
> 
> 
> actually at the Point where a layer Way Connects to an layer=0 way both are at the same height (e.g. where a bridge starts)


currently the assumption that everything meeting in a node is physically at the same 
elevation in this point is not valid in OSM.
It is broken by definition in at least one case: waterways ar supposed to 
share a node with the dam they are crossing, which means the highway passing 
across the dam will also share a node with the river passing thorugh a tunnel
or pipeline bellow it.

Some objects (such as dam, buildings) have the property to define their own 
physical level relations.


Richard