Introduce POIs from zoom 12

[nlehuby]

For now, the POI layer is quite on/off : nothing (except transport items) util z14, then, many POIs.
It would be great to add a few important POIs from z12, to allow a progressive display.
For instance, in Paris, we could have the Eiffel Tower, the Cathedral of Notre Dame de Paris and the Louvre museum at z12.

We could use wikidata and/or wikipedia to select important POIs :

• there is a wikidata property for the number of visitors, we can modify our current wikidata import to use this property to qualify important POIs and add them to the tiles from z12
• we can also/instead use wikipedia popularity by creating a new wikipedia import :
  • using the wikipedia articles page views statistics (webapp / data dumps)
  • or using the Nominatim wikipedia rankings

I've tried wikidata P1174 method and wikipedia page views method, by hand, in Paris, and both provide good results.

What do you think ?

[jirik]

+1 for adding important POIs at Z12+. We already started with railway stations and ferry terminals.

The thing is: How to decide what is important? Currently we use ranking computed by poi_class_rank. It's really not perfect, as it is based only on class of the POI.

We can combine the class-based rating with some other kind of ranking (e.g. popularity). An approach similar to current approach:

• assign class rank CR in range 1..N
• compute popularity rank PR in range 0..9
• compute total rank as rank=CR*10+PR

It's just a suggestion open to discussion.

Anyway, it would be good also to improve current class-based ranking, e.g. to rank transportation-related POIs with higher ranks. By the way, by adding amenity=doctors to hospital class, we increased popularity of doctor's offices much more than it should be.

[nlehuby]

My thinking was to compute the class rank and the popularity rank, and add them as is in the tiles to let each style designer define its own POI ponderation according to its needs.
But your proposal seems fine too.

Do you have any preconisation to create the popularity rank ?
If not, we may begin with the wikidata property because it's simpler (as we already have a wikidata import)

Do you want me to remove the doctors from the hospital class ? I'm the one to blame about this, and I agree, the doctors office are now quite over-ranked.

[jirik]

@nlehuby I would prefer to use one rank now, since it's closer to current state. Two ranks is interesting option for OMT 4.0.

I am afraid we do not have any preconisation, so please try what you think is the best option.

I have just remove the doctors, so it should be fixed: d48b623

[RilusMahmud]

Where and how is poi ranking defined? and can we change or modify the ranking as per our need?

[TomPohys]

Hi @RilusMahmud, POIs are ranked based on class https://github.com/openmaptiles/openmaptiles/blob/master/layers/poi/class.sql and if they have name https://github.com/openmaptiles/openmaptiles/blob/master/layers/poi/layer.sql#L45

For personal modification, please use Fork.