[OSM-talk] Layers and landuse

[Richard Z.]

On Mon, Jun 29, 2015 at 01:06:18PM +1000, Warin wrote:
> On 29/06/2015 9:34 AM, Martin Koppenhoefer wrote:
> >
> >sent from a phone
> >
> >>Am 29.06.2015 um 00:42 schrieb Warin <61sundowner at gmail.com>:
> >>
> >>If lower than the 'original ground level' then layer=-1 (or more)
> >
> >"layer" are tags to map relative local stacking (which object is above which other object where they overlap), it has nothing to do with original ground level. Where objects do not overlap, the tag is meaningless.
> >
> >
> There should be a reference point, so that what one mapper maps can be verified by another mapper.

this might look easy for simple crossings but in complex cases having layer=0
defined as ground level only complicates things.
People interpreting additional meanings into the layer tag causes more harm 
than good.


Richard