[OSM-talk] Mapnik Improvements regarding Tunnels

[Andy Allan]

On Nov 30, 2007 3:56 PM, Patrick Weber <p.weber at ucl.ac.uk> wrote:
> A) If you look at  the following Map Extract:
> http://www.openstreetmap.org/?lat=51.42871&lon=-0.07201&zoom=16&layers=B0T
> You can see that in the Mapnik layer, the Rail Tunnel is drawn above the
> elements that should lay over it like roads and parks. Can we have it by
> default that Rail Tunnels are drawn on the "bottom" layer, so that other
> elements can be drawn over it.

Can you confirm whether the railway has the appropriate layer tag?
Adding tunnel = yes doesn't automatically change the render order, as
far as I'm aware.

> B) The following map extract:
> http://www.openstreetmap.org/?lat=49.6101&lon=6.13291&zoom=17&layers=B0T
> shows a main road that becomes a tunnel in the middle section (you can
> check by switching to T at H layer). I dont know why this doesnt become a
> tunnel at all, again it would be great if that could get fixed.

It's not "get fixed", so much as having a new feature added (tunnels
for roads). See
http://svn.openstreetmap.org/applications/rendering/mapnik/osm.xml -
you can see that tunnels for railways, trams etc have rendering rules,
but there's no rules yet for road tunnels.

Cheers,
Andy