I have talked publicly about improvements to walking papers since at least SotM 2013. Made a blog post here in 2014 with some thoughts. But all I’ve seen were new ways to print tiles or atlases. While I admire the Field Papers and MapOSMatic fork improvements over the past years, a good walking paper is more than that.
For a long time I have been using a 28-step process to prepare walking papers for my mapping parties. It involved using Maperitive, Inkscape and some proprietary software. This year I finally got fed up with reanimating that old renderer, which doesn’t work perfectly on Linux, and tried something else. I had always been recommending QGIS for printing maps, and I decided to try it myself. Turned out, making walking papers with it is really simple and straightforward, albeit not without issues.
I started writing another guide with QGIS and GDAL and all the new tech, but it quickly grew to 22 steps. Still too many. Having discovered the Python Console in QGIS, I started experimenting with automating a few tasks. One thing after another, and now I have automated almost everything, fixing a few issues in QGIS on the way. I present to you…
It is the simplest way to prepare good walking papers for your mapping party. All you have to do is sketch the pie, and the plugin does the rest. Here are the complete instructions:
Amazing, right? For a regular mapping party this way of preparing walking papers gives you much more control, and you would need to do much less explaining when handing these sheets to participants. Here is why I prefer it to atlas-printing websites:
I hope this plugin helps you with organizing a mapping party. We know these don’t help with attracting new contributors, but parties are fun, you get to know your city or village better, and the amount of data you collect is unmatchable by any other data collection method.
Comment from tyr_asd on 5 July 2017 at 10:29
Very cool, but a main killer feature from the original walking papers is missing here (as far as I can see): the ability to automatically georeference scanned-in walking papers to quickly have them in an OSM editor as a background layer.
Comment from Zverik on 5 July 2017 at 10:57
I agree that the georeferencing feature is fun to have. But I don’t think it helps with entering the data: we have high-quality imagery for the most of the planet, and having the ability to look at both imagery and a walking paper simultaneously without clicking on a layer panel is a feature that comes free :) And as a bonus, you can rotate the sheet as you wish, when it is not digital.
Comment from GOwin on 5 July 2017 at 13:23
Excellent tips Zverik!
Comment from Steven Horner on 5 July 2017 at 16:30
Looks excellent from your post but it doesn’t work for me in Windows.
After I draw the polygon and select “Download OSM Data” again I’m asked where to save the OSM file, the layer disappears from the layer panel and if I look at the log message it says:
GDAL execution console output
Unable to open datasource `papers.gpkg' with the following drivers.
-> ESRI Shapefile
-> MapInfo File
-> UK .NTF
-> Interlis 1
-> Interlis 2
2017-07-05T17:23:19 0 GDAL execution console output
2017-07-05T17:24:21 0 GDAL execution console output
Data has been downloaded and saved into the OSM file.
Comment from Sam Wilson on 6 July 2017 at 02:31
I can’t find it in the QGIS plugin list, even with ‘experimental’ ones turned on. What am I missing?
Comment from GOwin on 6 July 2017 at 03:56
@Sam Wilson, the plugin is designed for an earlier version of QGIS you have in your computer. You might want to downgrade, or run a VM to try it out.
Comment from Sam Wilson on 6 July 2017 at 03:57
Ah cool, thanks @GOwin that makes sense. I’ll try with an older version. Thanks!
Comment from RobJN on 7 July 2017 at 15:39
Nice. Although I have never used the ability to automatically georeference scanned-in walking papers for my own mapping, I have seen the scans used at Missing Maps events.
Comment from Geonick on 17 July 2017 at 13:54
@tyr_asd: Just FYI: There exists a georeferencing tool inside QGIS and it’s is well documented. Here it’s of course a manual task. Now what about including a marker in the print composer which helps the user to georeference? That should be rather easy to program.
Comment from Geonick on 17 July 2017 at 18:50
@Zverik: I’m lost in your instructions when it comes to pie lines and areas… What do you all a “pie”? To me a pie is just a round thing…. What I expect here is, that a user just has to draw a perimeter (or task) as non-overlapping areas for each mapper.
Yay, we’ve got a map. Sketch the pie with lines in the “Pie Overview” layer.
Lines forming what kind of shapes?
Having finalized the pie, activate the “Pie Sheets” layer and draw areas
around quarters that go on each of the printed sheets.
How do these areas relate to pies lines?
Perhaps two screenshots showing an example of “Pie Overview” and “Pie Sheets” layer would help?
Comment from Zverik on 18 July 2017 at 06:50
Thanks, I agree that there is a misunderstanding coming from the absense of definition of a mapping party pie. It is merely a mapping area divided in parts, so each participant gets one part to walk around and map. A pie looks like this: https://wiki.openstreetmap.org/wiki/File:Pie-frunze-150711.png
You can draw pie and split it in pieces however you like. Sheets are parts of the pie that occupy the whole paper sheet, they are better to be rectangles.
Comment from Geonick on 18 July 2017 at 13:36
Many thanks. I see what you mean in the raster graphics and you mentioned areas (i.e. polygons with one outer ring and no inner rings) when drawing the Pies.
But how forgiving is your plugin? What are the constraints of the Pie Sheet areas? What happens if a sheet polygon overlaps the Pie Overview polygon and/or another sheet polygon? What if the sheets are larger than the layout A4?
Sorry for these silly questions - it’s s perhaps because of my professional deformation :-) in GIS…
Comment from Zverik on 18 July 2017 at 17:30
Pie Overview layer is just for the party organizer. It is not taken into account when preparing a printed atlas. I thought it would be useful to draw pie lines on it, so they are visible on printed sheets.
So all that my plugin does, it takes every feature from the Pie Sheets layer, rotates them so the scale is maximal, and adds to the atlas.