On Fri, Jul 31, 2009 at 3:42 PM, Tels nospam-abuse@bloodgate.com wrote:
On Thursday 30 July 2009 09:13:37 Daniel Kinzler wrote:
Hi all
I'm wondering if any thought has been given to rendering maps to SVG. I'm asking that especially in the light of http://techblog.wikimedia.org/2009/07/svg-for-all-with-flash/ which might give use in-browser display of SVG, and perhaps even interactive SVG. Using that with OSM would be really cool!
Now, afaik Mapnik supports SVG rendering. But I suspect that interactive vector maps would work differently from interactive pixel-based maps: you could scale smoothly, could use much bigger tiles, and would use level-of-detail layers instead of pre-scaled tiles...
Does somethign like that exist yet?
I toyed around with the idea, but I think SVG would not be able to handle a few hundred thousand objects that you get on zooming to level 11 and lower. Someone prove me wrong please :)
The trick, surely, is to filter the data at that zoom level so that you don't try to render too much.
When used with tiles@home, Osmarender renders place names for low zoom levels by working with a filtered dataset[1]. The place names are then superimposed on top of a captionless tileset that is derived by a separate process.
This link shows tiles containing just place names (major cities and countries) at zoom 5: http://informationfreeway.org/?lat=46.392704527927286&lon=9.361316960562...
You can imagine that it would be just as easy to render major features like coastlines and motorways using the same technique.
80n
[1] Providing such filtered datasets are one of the primary purposes of XAPI