[OSM-talk] Tagging "wide" steps (tribune / terrace)

[M∡rtin Koppenhoefer]

2010/6/6 Roy Wallace <waldo000000 at gmail.com>:
> On Sun, Jun 6, 2010 at 10:21 AM, Dave F. <davefox at madasafish.com> wrote:
>>
>> Off the top of my head I'm thinking of a line within the area that
>> defines the direction. it would have to be linked to the boundary by
>> using relations(?)
>
> Yup that is how I think also. Still no complete solution, but probably
> worth refining this, as a start:
> http://wiki.openstreetmap.org/wiki/Relations/Proposed/Area


yes, this is indeed one possible usage of this proposal: you could map
the beginning and end of each continuous steps. (this is 2 lines: one
indicating the lower end and one way following the upper end. In the
middle (horizontal areas with no elevation = landing) you could define
them as such (without even redrawing the ways). This enables as well
to map curved/multiangled steps, but still is problematic in cases,
where the steps intersect with a diversely inclined terrain (therefore
resulting in different amount of steps on the left and on the right
side). In the relation you could enter additional information
(steps=15) for the number of steps, to define it in ultimate detail
(optionally). Unfortunately no current renderer or router is able to
use this.


> Note that this will still not be a perfect solution for the
> semi-circular steps/terraces, because a way + area will not define the
> "curve" in each step.


yes, they will in many/most (exceptions see above) cases (according to
the area proposal you don't map areas as closed polygons).


 To do this explicitly, you'd probably want to
> map each step individually (as a curved way),


you would do this following the area-proposal, but you would probably
reduce it from "each step" to "each first and last step of a
continuity of steps".

cheers,
Martin