It's computationally a bit more expensive on the server, but you can have a tile server that makes the white areas of regular maps transparent and overlays them on top of relief maps (i.e. opposite order to what you tried). It's trivial PHP/GD code, and uses less CPU on the client-side than having semitransparent overlays (which can be *very* slow), but only works when the road map doesn't contain antialiased edges.
update: I found an example implementation, but it seems to be overlaying something with antialiased roads :( http://dev.openstreetmap.org/~ojw/relief/ On Tue, Apr 28, 2009 at 10:30 PM, Graham Jones (Physics) <[email protected]> wrote: > I have had a quick go at http://maps.webhop.net/srtm.html. It sort of works > - the high ground stands out, and you can see the shape of the ground, and > you can switch the overlay off and on. It does not work that well as an > overlay though because it is not really transparent enough. I find that > sometimes the transparency works quite well and you can see the map > underneath, and others it is practically opaque. _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
