[Talk-us-massachusetts] Rendering question

[Greg Troxel]

Marc Sevigny <marc.sevigny at gmail.com> writes:

> I have added lots of permanently protected parcels using JOSM.  One things
> I'd like to understand is why many of the parcels don't get rendered on the
> map until I zoom in a lot.  For example, if you go to
> https://www.openstreetmap.org/#map=14/42.5178/-71.5370,
> and look at the Black Pond parcel, not until you zoom in do you see the
> Vesenka Land, then zoom in more to see the Black Pond Access Land.
> Explanation?

You say 'rendered on the map'.  But really this expands to "shown on the
rendering which is used by the default tile layer on openstreetmap.org,
today".  There is a group that works on style rules for rendering, which
can be found at:
  https://github.com/gravitystorm/openstreetmap-carto

There has been some controversy over this over the years, mostly arising
from the fact that no one render can please everyone for all purposes.
So we have some blend of agendas and control with:

  what is actually tagged

  wha is defined to be tagged in the wiki

  what the standard style actually renders

In Mass, a major issue has been the wiki deprecation and non-rendering
of landuse=conservation, but we do it anyway because it is semantically
sound.

Then there is boundary=protected_area, which seems to be driven from
Europe and some legal framework they have, but more or less fits here
even though many think it is awkward.  But the carto folks may not be
keen on it and thus not render it at low zoom.

There is also some notion of omitting areas when they aren't that many
pixels at a given zoom.  That may be what you are seeing.  It's though
to be a feature :-)  But one person's clutter is another's critical
data, and this is basically intractable in general.

Finally, when the map is changed, some tiles are more quickly updated,
so if you are talking about things you changed in the last few days, it
may be different in a week.

Ways forward if you don't like this are:

  a) set up a custom render to make maps like you want from the db

  b) submit pull requests to the carto repo.  You'll probably have to do
  a to test.  These do not seem all that likely to be accepted if they
  are moving the style intent vs fixing bugs.
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