On Wed, Jan 27, 2010 at 9:01 AM, Bill Ricker <bill.n1...@gmail.com> wrote: > On Wed, Jan 27, 2010 at 2:13 AM, Frederik Ramm <frede...@remote.org> wrote: >> > I've noticed that a lot of bridges don't include a layer= tag. I >> > suspect this is because they render OK in mapnik...but not so well with >> > osmarenderer. (Consider the railroad >> > in >> > http://www.openstreetmap.org/?lat=33.76931&lon=-84.53762&zoom=17&layers=0B00FTF.) >> >> I'd suggest to modify Osmarender rather than the data, then. > > No this is Tiger import data, the data arrived wrong and was half > corrected. (much of tiger has intersecting nodes where there should be > bridges. some bridge insertion went without layering), It missing all but > implied layering of bridge-nature. What we can't tell without checking > satellite view is whether the bridge is at grade level with the Railroad in > a ditch, or if the bridge pitches up over the RR.
I wouldn't put any faith in when TIGER says something is a bridge. It seems like, in the process of merging tiger lines into single ways, no consideration was given to which segments were bridges. As a result, the entire length of the street gets "bridge=yes". Furthermore, this usually appears on roads with no obvious bridges (though there could be a tiny culvert somewhere along it) and not on roads that have bridges of any significant length. As far as I can tell, it could be completely random. Anyway, I have seen places where people have cleaned up freeway corridors, and neglected to tag "layer" on anything unless there are bridges crossing over other bridges. Mapnik renders this fine (actually that could be considered a deficiency of Mapnik in my opinion) but it looks a little goofy in Osmarender. (On the other hand, when one end of a "layer=0" bridge is directly at an intersection with other "layer=0" streets, Osmarender renders this beautifully and Mapnik makes it look odd.) Since some people consider the entire "layer" tag to be "tagging for the renderer" these people probably don't think it's important to add thorough layer information; instead, they add just enough to make it look decent in "the renderer". I am not of that opinion. -- David "Smith" a.k.a. Vid the Kid a.k.a. Bír'd'in Does this font make me look fat? _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us