On Fri, Apr 04, 2014 at 09:41:56PM +0200, André Pirard wrote: > Hi, > > Regarding normalized layers. > If I can believe my eyes, bridges/culverts are under (uninterrupted > foil) roads > <http://www.hdtimelapse.net/content/HDtimelapse.net_City/HDtimelapse.net_City_3290_hirez.jpg>: > > bridge=road-1. > Unless a renderer must assume that, which should be stated in the wiki, > then bridge=road. > If I can believe my eyes, 90° crossing rivers/roads run under bridges, > that is river=bridge-1. > Unless a renderer must assume that, which should be stated in the wiki, > then river=bridge. > A friend of mine says that we must start counting at 1 (like year 1) and > hence that ground=1 (;-)). > I'd like to know how many of you agree. While waiting, let's assume > ground=0. > > Hence, it depends very much on what the wiki states and we should settle > that before discussing. > Assuming assumption, we have road=0, bridge=0, river=0. > If the renderer does not assume anything we have road=0, bridge=-1 and > river=-2.
we don't have that. Perhaps you are concluding "uninterrupted level road" => same layer all along the road? There is no rule like this. You can split a completely level way into many parts and assign any of these levels a layer from -5 to 5 (you *should* use layer<>0 only for segments which are bridge/tunnel etc but elevation is not relevant). In addition, "key:layer" *is not* rendering layer/order. One example, a road is going through a forest, both should have implicit "key:layer" ==0. Obviously they still have a defined rendering order, otherwise our roads would disappear where they go through forests. If the road (for whichever reason, valid or not) has layer=-1 and the forest just the implicit layer==0, the road should still be drawn above the forest. Richard _______________________________________________ Tagging mailing list [email protected] https://lists.openstreetmap.org/listinfo/tagging
