[OSM-talk] New "Highways" view in OSM Inspector

[Jochen Topf]

On Fri, Jan 08, 2010 at 12:14:25AM +0000, Dave F. wrote:
> Jochen Topf wrote:
> >Long ways are a potential problem if you have long segments with no nodes in
> >it. One problem is when you draw a small part of the map that has a line going
> >through it but no nodes in it (because they are all outside), the line might
> >not show because the software doesn't recognize this. You can run into this when
> >using Osmarender for instance.
> I don't really like saying this, but isn't this a "don't map for the
> renderer" case?

I think "don't map for the renderer" is a nice idea, but has nothing to do with
the real world. People *do* map for the renderer all the time. I have long ago
given up on the idea of having perfect data somehow separate from the
rendering. Today my thinking is: Let people map for not one renderer but many
many renderers. The more renderers we have and the larger the differences
between the renderings are, the more we get to useful and versatile data. The
OSM Inspector is one of those renderers.

It comes down to what you think the OSM Inspector is. For me its a debugging
tool. It helps find actual and potential problems. It can only be one tool in
many. It supposed to help humans solve problems not fix them all by itself. You
can't just go through everything that shows up in OSMI and fix it according to
some perfect rule.

If a road doesn't show up on the map, you can look at OSMI and see that its a
very long straight road and the reason *might* be because it has no nodes in
your bounding box. OSMI doesn't do more or less. If you care about this aspect
of OSM data you can change the OSM data, if you don't, you leave it alone. OSMI
is trying to give you information about the data thats hard to see otherwise.

> >Another problem ist the projection. Straight
> >lines on the earth are not necessary straight lines in some projections. They
> >should show up as curves. But if you don't have enought supporting nodes, you
> >don't get nice curves.
> What projection does a map such as mapnik etc display apart from
> directly above?

Mapnik and many other renderers can display about any projection you can
think of and then some.

Jochen
-- 
Jochen Topf  jochen at remote.org  http://www.remote.org/jochen/  +49-721-388298