cannot render tiles with joined pmtile file created from "tile-join" command

[allmemes]

Version: tippecanoe v2.78.0

Context:

I have two polygon/multi-polygon geojsons: one representing the US states, and the other one representing the major cities/townships in US. Both have the same attributes. Originally they both come from one single table that I have, in that states geometries can overlap cities geometries a lot. I was trying to create a single pmtile file to include those two types of aois, but the tippecanoe creation takes really long time, probably due to large max zoom level that I set up.

Thus, I partitioned my aois and created tiles for each aoi types, namely state aoi and cities aoi, and I want to join them at the end. Just like the state and country example in the tippecanoe readme section. At last, I will self-serve this joined pmtile file with pmtiles library in a python fast api server, and I will consume this tile in a mapbox map, with the aim that in smaller zoom level, I show states. In larger zoom level, I show cities only.

Data:

State aoi:

I ran tippecanoe -o state.pmtiles state.geojson -z7 -Z3 --no-tile-compression -l state --no-tile-size-limit --no-feature-limit --buffer=0 --coalesce-densest-as-needed --extend-zooms-if-still-dropping

It shows:

51 features, 4883417 bytes of geometry and attributes, 17 bytes of string pool, 0 bytes of vertices, 0 bytes of nodes

During tile creation, no error or warning is triggered. and I can serve and render it normally in mapbox map from zoom level 3-7.

Cities aoi:

I ran tippecanoe -o city.pmtiles city.geojson -z14 -Z7 --no-tile-compression -l city --no-tile-size-limit --no-feature-limit --buffer=0 --coalesce-densest-as-needed --extend-zooms-if-still-dropping

It shows:

66140 features, 216173380 bytes of geometry and attributes, 16 bytes of string pool, 0 bytes of vertices, 0 bytes of nodes

Again, during tile creation, no error or warning is triggered. and I can also serve and render it normally in mapbox map from zoom level 7-14.

Tile joining:

After I confirmed both tiles work individually, I joined those two pmtiles to create a new one:

tile-join -o state-city.pmtiles state.pmtiles city.pmtiles, during which there is a warning that says zoom levels mismatch before and after joining.

When I load this joined tile into mapbox, with extra care on the 'source-layer' attribute in mapbox vector tile api to make sure the name matches. But I got error {error {message: 'Unimplemented type: 3'}.

Question:

Why do two tiles work normally separately, but error out when I used their joined version? How to exactly join two pmtiles and output one joined pmtiles for rendering? What optional params am I missing or misusing in the workflow above?

What I have tried to fix:

• tried .mbtiles for input and join, encountered the same issue, two tiles can render normally. But error out when rendering the joined tile.
• tried setting -zg for the cities.pmtile creation, in order to better mimic example in the readme. Still the same rendering error in mapbox map.

Any hint is appreciated, thanks. If this is not a proper place to ask question, would someone guide me to a place for help? Thanks and sorry if that is the case.

[e-n-f]

The "unimplemented type 3" is because you have used --no-tile-compression but the renderer is expecting compressed tiles, or vice versa.

You probably also need to use tile-join -pk because you have used --no-tile-size-limit with tippecanoe. Tile-join unfortunately quietly drops too-large tiles unless you use -pk.

[allmemes]

I just started simple over again:

1, I removed --no-tile-size-limit --no-feature-limit --buffer=0 for individual tile file creation.
2, I completely followed the zoom level in the county-state example in readme.
3, I added --overzoom --no-tile-compression to tile-join.
4, I added them in mapbox as source and load each layer within.

it seems to be working. I am exploring gradually to add back param like --no-feature-limit.

So thanks for your response! But still, I am working on improving the speed of tile creation. Would you mind give me a few hints?

1, Is it correct that:

• the larger the customized max zoom level it is.
• if we do not drop exceeding features, ie include --no-tile-size-limit --no-feature-limit,
• when data is highly overlapping.
  then the tile creation will be slow?

2, I do noticed that there are --read-parallel -P optional params. Does more cores help in tile reading or tile creation? I did turn geojson into geojsonl format, but I encountered EOF warning when I play around with those params.

3, should I partition my geometry data, then create separate tiles and join them at the end to serve large/complex data by different zoom level ranges? or should I just create one big tile from the beginning?