Most of my imagery is at an angle, so I have to be careful to map the building footprint, but this also means I can easily see the roof overhang on most buildings, so it is easy for me to map most of them.
If it was directly overhead, most of them are cantilevered roofs with very thick supports that are easy to spot protruding from the actual warehouse wall, so spotting the “roof” on most of these warehouses is pretty easy.
On Jan 10, 2019, at 11:54 AM, Graeme Fitzpatrick <[hidden email]> wrote:
as it's impossible to tell from an overhead image what is enclosed building
My understanding of the 3D aspect of building:part is that if you draw a portion of a building using building:part you have to do the rest of the building using building:part as well or the whole building will not render in 3D, since 3D software is programmed to ignore the base building footprint if building:part is present, is that correct?
On Thu, Jan 10, 2019 at 2:01 AM Martin Koppenhoefer <[hidden email]> wrote:
sent from a phone
> On 10. Jan 2019, at 03:42, John Willis <[hidden email]> wrote:
> - map the building as a warehouse and map an attached polygon as the roof (which I haven’t done yet).
I would do it like this, or maybe map everything as a warehouse and the roof as building:part
I am tracing and repairing existing traces of warehouses in an
On a slightly different but similar subject.
To do serious fast building tracing, one should use JOSM with Area
Selector Plugin 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
While doing that I also make lots of corrections to traces by other
OSM editors with a 2, 5 m or more precision error.
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.
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
This raises a problem.
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? I asked Paul
to add conflation. He did it, but with no tag merging.
I suggested that Area Selector simply invoked
Replace Geometry instead.
If you feel that conflation is important, please visit these pages
and back these requests.
Many of the warehouses have large (3-6m) roofs over
the loading dock gates, making the building appear bigger.
if it was just a storage warehouse for a random company, it would be impossible, but these are easy.
building=yes on the whole lot of it. Maybe add a "note=warehouse?
and part building=roof, layer=1”?
we do have building=warehouse, an iD preset with it’s own custom icon.
if the building and roof share nodes, and there is no driveway expected to be mapped under it, is the layer=1 necessary?
Or try to get UltimaSnorlax to fix them?
Thankfully, they are not slathering my area in mangled polygons and non-existent tracks anymore - I asked them to clean up their work, but they never responded.
they did map some named POIs that were a good addition, but almost every single way and polygon they drew has to be erased or heavily edited - and they were prolific for a year or so. Thankfully they stopped mapping a few months ago. They were all about mapping for z10, and by z13-15 it looked like a toddler’s crayon drawing. I’d rather clean up their mess than discover another 300 track ways through rice fields that don’t exist, or waterways mapped as highways; all of them half-sharing nodes with each other and every building and waterway that happen to be near the bird’s nest of ways he was creating.
Actually, you can, especially if you have imagery from multiple platforms at different times of year, or better yet, different times of day.
Shadows are usually the primary clue. Partial obstruction of other objects in the scene is another - like a semi-trailer truck poking out of a roof. Pavement staining and tire marks from fork lifts. slopes of piles of material along walls. Footpaths in snow., or if snow accumulates on the roof. Stacked containers. If you have evening or night imagery, the light silhouettes cast through windows to the outside. The presence of HVAC equipment and ducting on the roof, and roof materials in general. Obscuration or disturbance / distortion of vapor plumes from vehicle exhaust or furnaces.
All this falls under 'aerial photointerpretation'. The ones I mentioned above were from a WW II military training manual, some of the 'key' guides now are thousands of pages long.
Thanks Michael - you must access to much better aerial imagery than we do! - it's sometimes hard to even make out the actual outline of the building, let alone heat blooms! :-)
Seriously though (& not arguing :-)), "a semi-trailer truck poking out of a roof. Pavement staining and tire marks from fork lifts" wouldn't really be enough to say definitely whether you're looking at a roof over an open area or an enclosed building, would it? That truck could be poked out of the doors of an enclosed loading dock, & the forklift could be doing the same?
Yes, if you've got slanting or night time imagery that may help, but I've never seen it in the areas I map in :-(
On the subject of clarity of images. Was mapping the other day (using iD), marking buildings in an industrial area. As I said, the photo's weren't the clearest, but I was also peering through the purple haze of the mapped area=industrial, which certainly doesn't help matters either :-(
Does anyone know of any way of making that disappear / clear away (apart from deleting the area, & re-creating it after doing the buildings etc, which is a hell of a lot of work :-()
On Fri, Jan 11, 2019 at 10:34:40AM +1000, Graeme Fitzpatrick wrote:
>On the subject of clarity of images. Was mapping the other day (using
>iD), marking buildings in an industrial area. As I said, the photo's
>weren't the clearest, but I was also peering through the purple haze
>of the mapped area=industrial, which certainly doesn't help matters
>Does anyone know of any way of making that disappear / clear away
>(apart from deleting the area, & re-creating it after doing the
>buildings etc, which is a hell of a lot of work :-()
I don't know a way with iD, but with JOSM you can use its filter
capability to hide any elements (by filtering on tags) that you do not
want to be visible for the task you are performing at that moment.
On Jan 11, 2019, at 9:34 AM, Graeme Fitzpatrick <[hidden email]> wrote:
Was mapping the other day (using iD), marking buildings in an industrial area. As I said, the photo's weren't the clearest, but I was also peering through the purple haze of the mapped area=industrial, which certainly doesn't help matters either :-(
press “w” on the keyboard. toggles between the default “partial fill” view and Wireframe view.
I only map in iD, and leaning that helped a lot when mapping small details, and switching back to “partial fill” lets you see what tags are on ways and polygons.
JOSM you can use its filter capability to hide any elements
iD has a rough type hiding ability, “map data” icon on the right (“F” key shortcut), and has 12 categories of elements you can turn on and off. I keep boundaries turned off, for example - they are usually adjacent to ways I am working on and don’t want to accidentally join a node, nor do I want to ever edit them. if I try to move a node it does share, I get a dialog warning I am trying to modify a hidden object.
On 10.01.19 11:28, Allan Mustard wrote:
> My understanding of the 3D aspect of building:part is that if you draw a
> portion of a building using building:part you have to do the rest of the
> building using building:part as well or the whole building will not
> render in 3D, since 3D software is programmed to ignore the base
> building footprint if building:part is present, is that correct?
Yes, that is correct (according to Simple 3D Buildings tagging).
So if you want to represent the situation in question as a building with
two parts, you could draw a building:part=roof area for the roof, and a
building:part=yes area for the rest of the warehouse. Then surround both
of them with a building=warehouse area, probably re-using the nodes of
the building parts.
Some 3D renderers will attempt to figure out what the mapper might have
intended if this rule isn't followed. But that's undefined behaviour and
will vary considerably between programs, so it shouldn't be relied on.