On Mon, Mar 17, 2008 at 4:36 PM, Steve Hill <[EMAIL PROTECTED]> wrote: > > > Contours layer presented by openpistemap is simply great. Does it > > exist a server publishing only this layer? > > I'm not sure how that would work - you really need the contours data set > to be the bottom layer, with the normal layers on top of that (is it > possible to ask OpenLayers to render the OSM Mapnik tiles on top of > another layer? I suspect not since the tiles aren't transparent...) > > OpenPisteMap only has contours data for specific areas because > the data set is pretty enormous (I did try converting the whole SRTM3 data > set to shapefiles - I gave up by the time it had done about 3/4 of Eurasia > and sucked up over 100 gig of disk space. I haven't tried pulling the > whole data set into PostGIS yet - I wonder if that is any more efficient). > > Another consideration is that the contours tiles have to be tailored to > the map type a bit - for example, the cycle map renders the contours > closer together (i.e. it introduces each set of contour lines at lower > zoom levels than the piste map). The mountainous terrain of the pistes > results in unreadably close contour lines if you just try to apply the > cycle map styles. >
There's also the amount of time it would take to render the tiles. It takes over 15 hours to render the contours used on the cycle map, and all things considered that covers a very small % of the planet surface at any kind of decent zoom level. It's a slow enough process that render on demand doesn't work so well either. So any such server would need a few TB of disk space or be a "come back in 24 hours" after request job, or both. _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
