[OSM-talk] Nested areas

[Steve Hill]

On Thu, 5 Jun 2008, spaetz wrote:

> Why should it work differently? If I want a tunnel under a forest, a 
> layer=-1 *should* draw the tunnel under the forest.

It isn't in a tunnel though - if it was, it would have tunnel=yes. 
layer=-1 is often used for waterways for a couple of reasons:

1. It indicates it is below the _general_ level of the local ground (note: 
this does not imply it is a covered tunnel)
2. It means that ways which pass over the top don't need to explicitly be 
moved to a higher layer, which makes editing easier.

I don't think areas, such as landuse, natural, etc. should be considered 
as something physically laid on top of the land - they merely describe the 
use of the land within them and thus should not obscure other objects any 
more than the land itself should.

If the land itself isn't obscuring objects, why should an area tag, which 
effectively just describes some properties of that land.

  - Steve
    xmpp:steve at nexusuk.org   sip:steve at nexusuk.org   http://www.nexusuk.org/

      Servatis a periculum, servatis a maleficum - Whisper, Evanescence