[Talk-ca] Canvec Product - osm format

Sam Vekemans acrosscanadatrails at gmail.com
Wed Mar 10 14:38:14 GMT 2010


Interesting ideas.

Great to see i diagram explaining the different approaches.
I also want to point out that the WMS layer for all of this data is
available, so it is possable to trace over it, so to get the map features
that way.   This option is handy for working on areas of high density, where
loading the .osm file would make it harder to see exactly what features are
needed.

I would go for the 3rd option

*Partial integration model*: all geometries are complete by themselves.
Integration at coordinate level eliminates duplicate nodes. Overlapping
lines segments are duplicated. The model however allows the selection of a
subset of entities for data import.

As this allows for more maneuverability, and deeper  the integration with
other features.   We know that most of the road network has already been
imported, as that requires a different process.   For roads that are
missing, it seems just as easy to trace over.

When importing on Vancouver island i found that having the features separate
was best, since we like to have room to expand & add in more features.  ie.
if there is a fence around a wooded area & between the water, we would want
to map out those also.

Because these are 2 seperatate features, they should not be joined at the
hips.  And it's OK to have the polygons lined up end to end.

Im working a little bit in Princeton, BC
http://www.openstreetmap.org/?lat=49.45842&lon=-120.50942&zoom=15&layers=B000FTF
Where you can see that i was tracing from the Toporama WMS layer.   Once the
number of ways started to get to big, i connected it across the river to
make a full polygon.

Remembering that we 'dont map for the renderer' you can see that you cant
tell were it was that i made the plit.   I still wanted to get the detail,
but having it all as 1 big huge river polygon wouldn't make sence.  I only
wanted to map the in-town portion of it.   Once the .osm files become
available, then i can select only that large polygon & slice it so it doesnt
interfer with my tracing work.

The fact that there is the river-bank area & some sand areas along, it will
be fine to copy those polygons directly onto the map.

So in sum, regarding duplicate ways/nodes.  I only see it as a duplicate
when the way/node is part of the SAME feature.  If it is connected to
another feature, then i dont see that as a duplicate.
... but that's just me.   .. unless someone else has a better explaination?


Cheers,
Sam

On Wed, Mar 10, 2010 at 6:04 AM, Bégin, Daniel <
Daniel.Begin at rncan-nrcan.gc.ca> wrote:

>  Bonjour tout le monde,
>
> I've started to document the Canvec.osm product in the wiki.  I'll use the
> Canvec related pages to do it http://wiki.openstreetmap.org/wiki/CanVec.
>
> The geometric data model is open for discussion
> http://wiki.openstreetmap.org/wiki/CanVec:_Geometric_Model
>
> The proposed tagging will be updated soon in the corresponding Canvec:*
> pages
>
> I'm inviting you to look at the documentation and comment on appropriate
> discussion pages on via this mailling list.
>
> Cheers,
>
> Daniel
>
>
>
>
>
> _______________________________________________
> Talk-ca mailing list
> Talk-ca at openstreetmap.org
> http://lists.openstreetmap.org/listinfo/talk-ca
>
>
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