Kenneth Gonsalves <[email protected]> writes: > On Friday 23 Jan 2009 6:00:08 pm Sven Rautenberg wrote: >> > if the way is "layer=0" and the bridge is "layer=0" too >> > (the crossing way under is "layer=-1", digged) >> > then the bridge has no ramps. >> >> Something with negative layer has to be a tunnel. Bridges are useless if >> there is a tunnel. Do not tag bridges as "layer=0" just because there >> are no ramps. The layer tag is to help a renderer put the ways in the >> right visual order - not to indicate whether or not a way is elevated or >> not. Do not tag ways as "layer=-1" just because they are below the >> general earth surface (such as rivers). > > this is important - only underground rivers should be given a -1 layer tag
Yes, it has been pointed out many times that layers are relative only and have nothing to do with elevation. They describe whether some object is directly above another and not whether it is higher than another one nearby. Generally, I regard the earth's surface -- natural or not -- as layer=0. That means that a bridge which is completely level with the surrounding area is still layer=1 (at least) because it is above the ground. Matthias _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
