Generate basemap with richer/more specific tags/layers

[adamcohenhillel]

I am looking for a way to generate a custom basemap with some specific tags that exists in OSM but doesn't exist in the Protomaps Basemap, for example -> tag:amenity=shelter (https://wiki.openstreetmap.org/wiki/Tag:amenity%3Dshelter)

Any resource on how to do that?

I guess I need to change/add something in tiles/src/main/java/com/protomaps/basemap/layers, but not sure what and how. Any help would be awesome!

Thank you

[wipfli]

Hi @adamcohenhillel. A good start can be to search for amenity for example here: https://github.com/search?q=repo%3Aprotomaps%2Fbasemaps%20amenity&type=code

Now it depends if you would like to add points or polygons. For points, you probably want to add it to the POI layer, for polygons, maybe the Landuse layer could be good. Let me know if you have further questions...

[bdon]

@adamcohenhillel our long term goal is to make the basemap extensible for specific use cases, but there's no framework around that yet.

The easiest pathway is right now is to overlay OSM shelters as a GeoJSON or PMTiles dataset separately from the basemap, is there a reason you need it integrated directly into the basemap?

[adamcohenhillel]

Hey @bdon , thanks for the reply! It doesn't have to be integrated directly into the basemap, I can add a separate overlay. My use-case is basically add/remove different annotations to/from the map, based on a user clicking a button.

Do you have by any chance an example for how to add a simple overlay from OSM on the basemap? (either as a GeoJSON or PMTiles dataset, whatever is easier).

I am using the MapLibre GL

[bdon]

for amenity=shelter you could grab GeoJSON from an Overpass API instance and then pass the GeoJSON into https://github.com/felt/tippecanoe to create PMTiles.

[wipfli]

@adamcohenhillel can this issue be closed?

[bdon]

We eventually want to make the basemap generation extensible via configuration but this is on the medium/long term roadmap. OK to keep this issue now so we can collect requirements.

[EconomicTouristsArmLate]

I also have the need to customize things. My changes to the basemap only involve the POI-layer: adding domain-specific places, removing places irrelevant to the domain at hand.

I would assume that holds true for the vast majority of usecases -- any other change I want to make to the basemap (eg there are issues with way too prominent labels on very insignificant water bodys) would always be better placed in a contribution upstream / here.

Maybe this reduces the scope of the problem to a more manageable & useful one, at least for an initial implementation.

---

The easiest pathway is right now is to overlay OSM shelters as a GeoJSON or PMTiles dataset separately from the basemap, is there a reason you need it integrated directly into the basemap?

I am not fond of that workflow, in the situation where the POI in question are already contained in the pmtiles data (which many are, thankfully). Adding another layer would just increase overhead.

So my preferred workflow I'm aiming for is forking the style.json, or better, generating a customized style-json via some typescript API provided by protomaps/basemaps.

This raises the question: why is there data in the tiles that is not rendered? Future direction of the protomaps tiles probably needs to decide between

1. enabling easy customization via a workflow as i described above
2. matching the tile data closely to the style, and point users to external datasources for additive customizations.
3. providing a templated tile-generation pipeline, where tiles only contain what is needed, both of which would be customized in sync. this seems to have huge complexity tho.

My preference is option (1) (because i'm not burdened with managing my own osm-extract-to-tiles-pipeline + the complexity of merging labels of multiple sources for only a basemap-usecase).
But this probably needs some benchmarking of the impact of additional POI on tile size, in order to make a good decision

[bdon]

are issues with way too prominent labels on very insignificant water bodys

Can you point these out specifically?

why is there data in the tiles that is not rendered?

If you mean POIs, simply because it's a work in progress, we have limited time to work on this and we haven't finished the POI layer yet.

enabling easy customization via a workflow as i described above

Most meaningful customizations would involve modifying the tileset in addition to the style.

Since the NPM package returns a set of MapLibre layers, you can already modify those programmatically at runtime.

[EconomicTouristsArmLate]

issues with way too prominent labels on very insignificant water bodys

Can you point these out specifically?

sure, will do soon™ in a separate issue.

why is there data in the tiles that is not rendered?

If you mean POIs, simply because it's a work in progress, we have limited time to work on this and we haven't finished the POI layer yet.
[..]
Most meaningful customizations would involve modifying the tileset in addition to the style.

ok, so those additional POIs are there temporary only. and longterm you intend to match the tiles closely to the base-style?

Since the NPM package returns a set of MapLibre layers, you can already modify those programmatically at runtime.

neat, i'll play around with that, and report if it worked out for my usecase.