- News from Peter
- Planet QGIS Plugin
- Vector Tiles coming to QGIS 3.13
- The Mapscaping Podcast
- Using Vector Tiles with Tegola and Amazon S3
- Historic Puget Sound Commuter Rail
- Graphical Modeler
The October meeting was held via Zoom. We had a good crowd attending with ten people attending, including at least one first timer.
Peter shared three interesting QGIS links that he came across
- Planet QGIS plugin presentation from PDXOSGeo
- Lutra Consulting has secured crowd funding to add vector tile native support in QGIS. They are targeting QGIS 3.14, scheduled to be released in June 2020.
- The Mapscaping Podcast, a great GIS podcast to check out.
Using Vector Tiles with Tegola and Amazon S3 - Stephen Mangum
Stephen has been working on a project to map the age and distribution of housing in central Puget Sound. Due to the size of his data, he had trouble getting all of his parcels loaded into QGIS. While he continues to use QGIS to prepare and edit his data, he is now displaying it with a web map.
His first attempt was to use Mapnik to create raster tiles, but he found the result wasn’t interactive or easy enough to update. Next based on Gretchen Peterson’s tutorial, he tried using Tegola tile server to create vector tiles that were cached on Amazon S3. With this solution he manually processed each piece of data making it difficult to update when new data became available. It also required the expense of running an accessible PostGIS server at all times.
Stephen is hoping to be able to load his tiles into QGIS, but has not had success using a plugin he found. Possibly the native vector tile support mentioned earlier by Peter with provide a more robust solution. He continues to work on the presentation to better communicate the story of the data.
Stephen is sourcing map labels from OpenStreetMap, exporting them using GeoFabrik. Currently he is using only the point features for buildings finding that they provide more relevant labels than the polygon features.
Historic Puget Sound Commuter Rail
There was a discussion of sources for locating former trolley and inter-urban rail liens that formerly served the Puget Sound area in the first half of the 20th century, which Stephen has been researching and digitizing for inclusion in his housing map. Stephen found the most value in the Seattle Municipal Archives, and the 1936 aerial photos available from King County. Patrick suggested he check out the Trolley Trail, a Burien Streetcar map, as well as try to contact David B Williams. Paul suggested the King County Roads Map Vault but Stephen hadn’t had much success with that.
Peter has experienced some trouble using the graphical modeler in QGIS to process data that he downloads from the internet. He would like to model it, and then export the model as a script of some kind. Evan suggested using the the refactor fields tool in model builder under vector builder, but cautions is may be broken on MacOS. Evan keeps a Linux virtual machine on his Mac specifically to address this problem. Evan also counseled that QGIS assumes a model will have one input and one output, unlike the Esri model builder tool many are familiar with. There is a facility for batching inputs and outputs and feeding them to the model one at a time.