[OSM-talk] Segments, Ways, and the data model

[Andrew Findlay]

On Sun, Sep 24, 2006 at 11:32:34PM +0100, Etienne wrote:

> Think of ways as a replacement for segments.  Segments can have only two
> nodes.  Ways can have as many nodes as you need.  So ways are better than
> segments.  One day soon ways will be re-defined as a list of nodes instead
> of a list of segments.  Then all segements will be replaced by ways with
> just two nodes.  After that, no more segments.

If that is going to happen then I think the editors need to be modified
to make it easier to merge and split ways. There are large parts of the
world at the moment with just segments, and it would be a daunting task
to update such an area if it suddenly *looked* as if everything was ways
but in fact all the ways had just two nodes...

While talking about the data model, is this also the time to start
thinking about a layered system? Increasing use of Osmarender to
produce nice maps is going to result in increasing use of areas, and
when editing these look just like ways but they don't join up with
others so the display in JOSM etc can get very confusing. I would
like to see the data split into (at least) a ways layer and an areas
layer. Better still would be to define layers by the type of feature
being represented, so we could separate out boundaries, built-up
areas, land features, points of interest and so on. People producing
maps could then easily select which ones to render, and people
editing the data could avoid getting confused by features that are
not relevant to the task in hand.

Andrew
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|                 From Andrew Findlay, Skills 1st Ltd                 |
| Consultant in large-scale systems, networks, and directory services |
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