Re: [OSM-talk-ie] Dividing houses with returns as terrace (Brian Hollinshead)
Hi Brian, I was very happy to see your message as there doesn't seem to be a lot of love out there for careful drawing of building shapes. Understandably, it can be time consuming and I occasionally do some architectural drafting for a living so I'm definitely biased and in a better position than many to tackle this. It may help if I list general tips I've developed to overcome the very limited tools in JOSM for aiding with this task. Some of them involve improving results by not using the obvious way, such as using a tool not intended for a result to ultimately get that result while leaving clean geometry and tags. Install the following plugins for JOSM: alignways, building_tools, terracer, utilsplugin2. With all of these installed you now have these useful commands to help create good quality building shapes: Orthagonalize Shape [q] (core) Create Areas [x] (core) Join Overlapping Areas [shift+j] (core) (referred to as 'merging shapes') Draw Building [b] (building_tools) Split-Shape [alt+x] (utilsplugin2) Add nodes at intersection [shift+i] (utilsplugin2) Terrace a Building [shift+t] (terracer) Align Ways (alignways) I'll run through general techniques I use and I'll answer your question at the very end. You can skip straight to it but it might make less sense without the following. I'm basing all techniques from tracing Bing Maps: 1/ With some exceptions, building are nearly always orthogonal or have angles that mirror others. It's easiest to draw them as orthagonal and then create any other angles afterwards where confident. 2/ With the above in mind, I generally draw buildings using a series of independant rectangles which I then merge into a single shape at the end. This includes returns and any extrusions. While you can draw a perfectly perpendicular return from a building by adding two nodes to a rectangle and extruding the line between them using 'Create Areas', if you draw the return as a seperate rectangle and merge it to the main house at the end, you have slightly more flexibility with moving the return around as seperate rectangle than you do with nuding points and ways on the same shape if it was extruded. 3/ Get familiar with using the 'Draw Building' too for blocking out the shape of an entire building using rectangles that overlap. If you have a rectangle selected and begin drawing a new rectanlge using 'Draw Building' it will keep the new rectangle's angles lined up with the selected one. This is a huge time-saver and helps with accuracy. Where a more complex building is not perfectly orthagonal I find I'm often drawing a group of rectangles that are based on two different rotations. The 'Draw Building' tool helps me keep to these two different rotations throughout. The original architects usually followed patterns with angles and you can spot these pretty quickly. 4/ Don't forget you can quickly orthagonalise a shape by selecting it and hitting 'Q'. If you select a shape and then select any two nodes on this shape or another before hitting 'Q' the shape will be orthagonalised and aligned to the same angle between these two nodes. Very useful with terraces or quickly using other shapes as angle guides. If you don't select two other nodes the shape will be orthaganalised to the average of all the angles in the shape. It's worth knowing that architects often based the angles of a building on neighbouring buildings so try using these as guides and see if they help. 5/ I predomiinantly use 'Create Areas' to nudge entire lines parallel to their origin rather than using them to extrude lines from others. So If I've drawn one rectangle as a house and another rectangle as a return. I'll drag the return into place and resize it by nuding its boundaries using 'Create Areas' on its lines. 6/ To expand on this tip, if you hold down 'alt' while using 'Create Areas' to either nudge a line or extrude from between two points it will create an entirely new shape that's glued to the old. This is immensely valuable. I use it for creating terraces (I'll elaborate on this) or for creating guides which I'll later delete (ditto). 7/ One area I do use 'Create Areas' for is extruding a return rather than drawing a seperate rectangle then merging is at the edge of a building. It's quite quick to align one rectangle with another if you zoom in to the full extents and make sure the way of one rectangle lines up with the way or node of another. If I attempt any merging of shapes after this JOSM treats this level of alignment as being the same coordinates on both. However, at the edge of a building it can be quicker to just extrude a return rather than zoom in and align a seperate rectangle. My exception to this is if two returns meet on a terrace (I'll elaborate on this). 8/ I always draw to match the roof-top outline of a building and then drag the finished outline to match corner where the building meets the ground. Be careful that
Re: [OSM-talk-ie] Dividing houses with returns as terrace (Brian Hollinshead)
Hi again Brian, On re-reading your question I see it wasn't so much a question on how to divide terraces for interest of including returns, so much as how to deal with dividing terraces where somebody else has already included extra returns. So my guide may not have much use for this question, apologies. Hopefully the tips are useful to anyone else who wants to improve building accuracy. To re-answer your question, perhaps emphasising that those including returns etc. take the time to correctly divide buildings at the time as it's easier to do so then than after. I know this isn't the most practical of answers but would be a good approach to follow in the future. Also apologies this isn't following the original thread on the archive. I've only got the digest version and can't see an option to reply to the original message other than manually placing it in the subject line (which didn't work for the archive it seems) Conor ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
Re: [OSM-talk-ie] Dividing houses with returns as terrace
On 8 August 2015 at 16:36, Brian Hollinshead br...@hollinshead.net wrote: I have routinely used the terracer plugin in JOSM to divide a long/single building into a set of terraced houses. Recently I was talking OSM to a librarian from Casimir Road, Harolds Cross, Dublin, I asked would he like to share the house numbers with me if I added the outlines first. He readily agreed. When I got home I found someone has already kindly added most of the buildings carefully showing the return in each case. I cannot get the terracer plugin to like trying to divide such a building into two equal rectangular halves. I have only ever achieved that by drawing a large outline of the terrace, then drawing the lines to split the houses and manually splitting the outline into several houses. Very tedious, so I don't bother these days, choosing to terrace as a block and add the house numbers, which I find to be more important than the shape. Regards, Nick ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
Re: [OSM-talk-ie] Dividing houses with returns as terrace
I hope I got the problem correct. if you do not have the house numbers yet, use the number of segments in the terracer plugin to split in even parts. When you have the house numbers, fill in the lowest highest number and choose even-odd/all. In this case you preferable select the building, the street, as well as one node of the building on the side where the lowest number has to come before opening the dialog. This only works for buildings that are nice rectangles. regards m On Tue, Aug 11, 2015 at 11:42 AM, Nick Burrett n...@sqrt.co.uk wrote: On 8 August 2015 at 16:36, Brian Hollinshead br...@hollinshead.net wrote: I have routinely used the terracer plugin in JOSM to divide a long/single building into a set of terraced houses. Recently I was talking OSM to a librarian from Casimir Road, Harolds Cross, Dublin, I asked would he like to share the house numbers with me if I added the outlines first. He readily agreed. When I got home I found someone has already kindly added most of the buildings carefully showing the return in each case. I cannot get the terracer plugin to like trying to divide such a building into two equal rectangular halves. I have only ever achieved that by drawing a large outline of the terrace, then drawing the lines to split the houses and manually splitting the outline into several houses. Very tedious, so I don't bother these days, choosing to terrace as a block and add the house numbers, which I find to be more important than the shape. Regards, Nick ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
[OSM-talk-ie] Dividing houses with returns as terrace
I have routinely used the terracer plugin in JOSM to divide a long/single building into a set of terraced houses. Recently I was talking OSM to a librarian from Casimir Road, Harolds Cross, Dublin, I asked would he like to share the house numbers with me if I added the outlines first. He readily agreed. When I got home I found someone has already kindly added most of the buildings carefully showing the return in each case. I cannot get the terracer plugin to like trying to divide such a building into two equal rectangular halves. Solutions/suggestions from those who have done this most welcome. Thanks ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
