Lennard wrote: What is >harder in mapnik, without explicit tagging, is determining when exactly >a road is under a building, and making a clean transition from normal >rendering to 'sheltered' rendering.
I would tend to leave that to the mapper, as long as the renderer can determine that the road does in fact intersect a building (or other object). The mapper should break the way at the building edges (or slightly outside, to avoid any computational problems), so that the renderer only has to take care of that segment. If more road is rendered as under something than should be, the mapper should be the one to fix it, in my opinion. It's only slightly different from a bridge. The mapper has to denote the extremities of the bridge. Granted one is explicit and the other is implied, but if you draw a road under another object, or add a building on top of a road, you as the mapper should be responsible for establishing the ends of the covered road. I've been considering this from a more global perspective, and, as a matter of fact, it might be a workable solution all around to just add a highway tag, "covered=yes", which would always be rendered as broken lines and transparent fill. That would be real easy for the renderer, and give the mapper explicit control. This would even work for another case I am aware of where the building has a small ground floor, with one shop, a stairway and an elevator. The upper floor extends over a parking area/service road. It's really not appropriate to break the building into two pieces, since the second floor is contiguous. I can think of other cases that it would resolve as well. How about a road that has been covered by a lake. It may be nice to have the submerged road marked to give anglers a general idea of where to fish (often along the shoulders of the road, especially if the road is either raised or lowered from the surrounding terrain)> -- Randy _______________________________________________ newbies mailing list [email protected] http://lists.openstreetmap.org/listinfo/newbies
