Christopher Schmidt crschmidt at crschmidt.net
Tue Apr 25 12:52:34 BST 2006

On Tue, Apr 25, 2006 at 10:29:39AM +0100, Tom Carden wrote:
> On 4/24/06, Christopher Schmidt <crschmidt at crschmidt.net> wrote:
> > Open Guide to London [1] data and planet.osm dump loaded into postgis,
> > set up alongside Google Maps (for a slippy interface) and served using
> > mapserver:
> >
> > http://crschmidt.net/mapping/ogl/sidebyside
> >
> > There's some weird projection issues, but I think those are Google Maps
> > related more than anything else.
> Google Maps uses Mercator as far as I'm aware (as do Yahoo Maps and
> Virtual Earth).  OSM does too.  There's a successful demo showing OSM
> layered on top of Google Maps somewhere... can you show us a screen
> shot of the issues you're talking about?  Looks OK to me.

Zoom in to a road. Put the cursor in the center of the Google Maps map.
Then trace south or north along the map. Note how the 'mirror' cursor
(slightly larger blue dot on the right hand side) doesn't match up to
the roads exactly.

I don't know anything about projections, I just know that I've had to
spend a couple hours dicking with converting the lat/long that Google
outputs to meters using forumlas helpfully provided to me by another
geo-interested friend, as well as mucking with the projections in
mapserver. Note that OSM is not being projected in Mercator here -- it's
being converted from epsg 4326 to 43210. I don't really know what this
means, I just know that's what I have to do. 

This is a problem with my code, not with the data.

> > OSM's api and WMS proved completely useless, and caused endless amounts
> > of frustration due to slowness and lack of documentation.
> The WMS documentation was out of date, true.  The REST API is pretty
> well documented though.  The WMS page on the wiki specifically says
> "bug the mailing list for more information".  I didn't see any
> messages about WMS recently - do you expect documentation to magically
> appear as soon as you need it?

The REST API is so slow as to be unusable, so that was out of the
question for my purposes. The fact that the WMS output has been changed
since it was created, but no one thought to mention that on the WMS
server page, bothered me. Is it fair to assume that someone will update
the documentation when the code changes? I suppose not, but it makes it
hard to have any interest in participating in a project where the 6
months old documentation description is no longer accurate. I asked on
the mailing list for what the actual limits were when they were
instituted months ago, and never got an answer.

> > I feel like it
> > must be possible to improve things beyond their current state so more
> > people can do neat stuff like this.
> True.  See the never ending threads about hardware and hosting - which
> are still yet to be resolved.  Hosting is pending, and the new
> hardware we have needs hosting.  So soon there will be more
> flexibility in the set-up... I imagine if enough people are interested
> in it then the chains could be taken off the WMS, or we could provide
> a static WMS based off the monthly DB dump as someone suggested.

Yeah, except this has been the case since the day I found the project.
"Can I donate money/hardware?" has always been a "Not yet, we're working
on it." I got tired of waiting, which is why I have no interest in doing
anymore here. I've asked 'can I host a part of the application?' and
been told no. I've asked "Can I donate hardware/bandwidth" and been told
no. What more am I supposed to do? 

I keep hearing 'wait', but what am I waiting for? Does this waiting have
an end somewhere?

> > Even just providing a mysql database
> > dump would have saved me valuable time, and allowed me to build on
> > existing work in the OSM project.
> Planet.osm is new this month.  It's likely that in the future it will
> come in different formats, but only if people request them.  A mysql
> database dump isn't as trivial as it sounds because it includes all
> the modifications - there isn't, AFAIK, a table with the 'current'
> view of the db - it's built on the fly.  So converting planet.osm is
> actually the best way to do it.

Is the database really so significantly overloaded that 'mysqldump
openstreetmap > file' is not possible at any time of the day? 

> >
> > After this work, I'm really frustrated with the external facing OSM
> > support
> This implies there is internal facing support!

There is, actually: The tile server has increased greatly in speed
recently, and it makes the site usable again -- for OSM's purposes. Yet
no effort has been put into making the site usable for any other
purpose, other than planet.osm (which is at least usable, unlike
everything else).

> > and I probably won't be doing any more work with it.
> Wow.  We're all volunteers and hobbyists here - your attitude sounds
> pretty childish to me.  "It sucks now, so I'm going home and I'm
> taking my ball with me!"

There's no ball to take home. OSM can't do what I need, getting what I
need out of OSM is damn near impossible, and there's no OSM interest in
utilities for persons not using the OSM server to increase the content
in OSM.

I wanted to be convinced I was wrong, and that there was avid interest
in developing utilities for non-OSM.org users. I haven't been yet, but
could be if anyone wants to. The fact that I haven't been says to me
that there's no interest in it, and without that, what can I do?

Christopher Schmidt
Web Developer

More information about the talk mailing list