I think the layer=-1 is a good trick in urban zones where you have many bridges. But is it necessary to add a layer -1 in the countryside even in sections where you have no crossing at all ? Anyway, is that the correct ML to discuss mapping rules ? Pieren
On Wed, Aug 20, 2008 at 11:24 AM, Dermot McNally <[EMAIL PROTECTED]> wrote: > 2008/8/20 Gervase Markham <[EMAIL PROTECTED]>: > >> I think that both waterways and roads are layer 0, "the ground", and >> when one crosses another, the upper one should have layer=1 - because >> there's air between it and the actual surface of the earth. I would >> apply this to any ground-based physical features, not just roads and rivers. > > That articulates my view pretty well. Once again, consider that > "layer" isn't the same as "level". We don't care whether a bridge > rises up above the "level" of the road either side of it. The > important thing is that at the point where it crosses the river, the > road must be on a higher "layer" than the river. So along the length > of a way, it is acceptable (and unavoidable) to have "jumps" in layer > that may not reflect actual changes in elevation. Layers exist to > determine the drawing order of overlapping elements, nothing more. > > Dermot > > -- > -------------------------------------- > Iren sind menschlich > > _______________________________________________ > josm-dev mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/josm-dev > _______________________________________________ josm-dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/josm-dev
