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<div class="moz-cite-prefix">On 2019-01-10 03:42, John Willis wrote:<br>
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<blockquote type="cite"
cite="mid:BC64D69C-B8CD-4166-8993-A0AC30A7EE31@mac.com">
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I am tracing and repairing existing traces of warehouses in an
industrial district. <br>
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On a slightly different but similar subject.<br>
To do serious fast building tracing, one should use JOSM with <a
moz-do-not-send="true" href="https://github.com/JOSM/areaselector">Area
Selector Plugin</a> and an orthorectified map such as PICC in
geoportail.wallonie.be or basemap.at. That goes, complete with
auto-incrementing street number tagging, at the rate of one house
per 5-10 sec, but needs occasional touch up with Improve Way
Accuracy tool.<br>
While doing that I also make lots of corrections to traces by other
OSM editors with a 2, 5 m or more precision error.<br>
This is partly because they trace roofs from aerial maps, which are
not at ground location because the camera view and walls are
slanted. But also the roads are affected by imprecision.<br>
Orthorectification does an incredible job of putting that right,
impossible to do by hand. It computes the slant angle in one place,
uses it in another, uses shades on the ground etc. I've seen it
detect in meadows banks (slopes) that were strictly invisible to the
eye.<br>
This raises a problem.<br>
When meeting untagged buildings that have been coarsely traced 5-10
m away from their position, should they simply be erased and
replaced in 5 secs or should 20+ sec instead of 5 be spent for
conflation?<br>
<a moz-do-not-send="true"
href="https://github.com/JOSM/areaselector/issues/23">I asked Paul
to add conflation</a>. He did it, but with no tag merging.<br>
I suggested that Area Selector simply <a moz-do-not-send="true"
href="https://github.com/JOSM/areaselector/issues/30">invoked
Replace Geometry instead</a>.<br>
If you feel that conflation is important, please visit these pages
and back these requests.<br>
<blockquote type="cite"
cite="mid:BC64D69C-B8CD-4166-8993-A0AC30A7EE31@mac.com">
<div class="">Many of the warehouses have large (3-6m) roofs over
the loading dock gates, making the building appear bigger. </div>
<div class=""><br class="">
</div>
<div class="">here is an example. </div>
<div class=""><a
href="https://www.openstreetmap.org/way/494766956" class=""
moz-do-not-send="true">https://www.openstreetmap.org/way/494766956</a></div>
<div class=""><br class="">
</div>
<div class="">if I am mapping this kind of warehouses, which
should I:</div>
<div class=""><br class="">
</div>
<div class="">- map the whole structure as a warehouse</div>
<div class=""><br class="">
</div>
<div class="">- map on the building portion as a warehouse (as I
have done)</div>
<div class=""><br class="">
</div>
<div class="">- map the building as a warehouse and map an
attached polygon as the roof (which I haven’t done yet). </div>
<div class=""><br class="">
</div>
<div class="">I am going to spend the time cleaning up
UltimaSnorlax’s bad polygons, I might a well draw them correctly
the first time. </div>
<div class=""><br class="">
</div>
<div class="">Javbw</div>
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