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I am unclear how I can name two or more parts of the same building separately. I found this example of what I want to achieve (where part is Halfords, part is BestBuy) but I don't understand how to achieve it. Any advice would be appreciated - thanks.

asked 17 Nov '11, 06:29

FollowMeChaps's gravatar image

accept rate: 0%


Many thanks to all. I think my main issue was that I was not closing the second set of nodes. Hopefully I've cracked it - see here where I've split the central building into a Cardiac and Laser centre. Tim's video was particularly brilliant as it hand-held me through it.

Onwards and upwards! :-)

(18 Nov '11, 07:01) FollowMeChaps

I do this all the time, using Potlatch 2. The easiest way is just to draw the outline of one shop/house, hit Q to square it up, then just start a second rectangle that shares one or more nodes with the first. There are plenty of examples here:

For a neater result, draw the outline of the whole building first, then split it into parts exactly as neuhausr describes above.

Edit: here's a quick screencast showing what I'm talking about. My last couple of words got cut off, but you'll get the idea. Enjoy.

permanent link

answered 18 Nov '11, 00:23

Tim%20Morley's gravatar image

Tim Morley
accept rate: 33%

edited 18 Nov '11, 00:49

Many thanks for the answer. I can do what you suggest in your first paragraph and it works - great. However, trying the whole building first doesn't for me - I must be doing something wrong. I'll do it para 1 in future.

(18 Nov '11, 06:26) FollowMeChaps

Many thanks Tim - the video at the end really cracked it for me - BRILLIANT. Just proves that a picture really can paint a 1,000 words!

(18 Nov '11, 06:54) FollowMeChaps

In JOSM I use the Terracer plugin. I would select the single rectangle, press Alt-T, set the plugin to create 2 units, delete the outer way, and don't create an associatedStreet relation. I would then drag the dividing line to where I want it to be, and probably press Q to make sure doing that has left the two rectangular ways as right angled.

In summary, whatever editor you are using, each area is a single way and they share nodes for the common wall(s). In Potlatch I'd probably make the single rectangle that exists the size of one unit, then draw the other unit next to it sharing nodes.

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answered 17 Nov '11, 08:47

EdLoach's gravatar image

EdLoach ♦
accept rate: 22%

Thanks Ed - I should have said I'm a Potlatch user.

(18 Nov '11, 06:38) FollowMeChaps

To split an existing building (or other closed way) in Potlatch 2:

  1. Select the building way
  2. If there are not nodes where you want to split the building, add them by shift-clicking on the way
  3. Select each node at the split and press X to split the way there
  4. Select one of the unclosed ways, click on an end node, then connect to the other end node to close the way
  5. Repeat with the other way
  6. Add tags (remember too you can copy the tags from the last way touched to the current one with the R key)
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answered 17 Nov '11, 15:40

neuhausr's gravatar image

accept rate: 21%

Thanks neuhausr. Try as I might I'm not sure that I can get this to work - it seems to always shows a conflict of names when I try to rejoin them. I'll play again and see if I can crack it. Perhaps I don't fully understand sharing nodes.

I'll report back - meanwhile thanks.

(18 Nov '11, 06:37) FollowMeChaps

Looking at your link I've just tried to repeat that in a blank space, but did not save it of course! so in potlach2 draw/trace half of building and use square tool then drag it away, draw the other half and square it,tag them, drag them back to accurate position save job done

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answered 17 Nov '11, 08:15

andy%20mackey's gravatar image

andy mackey
accept rate: 4%

edited 17 Nov '11, 08:16

I found it very hard to split an existing polygon/building to make separate polygons so I'm sure the answer is the easier method

(17 Nov '11, 08:24) andy mackey

The "j" function in P2 will connect the common nodes and wall to tidy up correctly

(17 Nov '11, 09:06) andy mackey
(17 Nov '11, 10:23) andy mackey

Many thanks andy. I now think I'm getting somewhere using a mix of all the answers. The J trick helped (I guess this is the same as the chain icon on the toolbar?). It's the joining shared nodes without getting a conflict of names that's the trick.

(18 Nov '11, 06:44) FollowMeChaps

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question asked: 17 Nov '11, 06:29

question was seen: 11,337 times

last updated: 18 Nov '11, 14:18

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum