I’m using 2 different sets of protobuf layers, one for lands and one for buildings, that I display using leaflet vectorgrid library. I can filter features styles using feature properties of each layer.
But I need the 2 filters to be connected to each other : when I filter lands, I would like buildings contained by the containing lands to be filtered too.
Do you see a way to do so?
Thanks a lot!
Sam
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I'm trying to create an experience where I have a couple of detailed 3D models of buildings on the map with extruded building footprints of neighboring buildings via a vector tile source. The 3D models would be the main focus point and the extruded footprints would be for reference. One challenge I'm running into is that I have a global building footprint layer and it has a footprint for the 3D buildings which doesn't match up perfectly. Additionally, when extruded, it ends up merging/overlapping the nice 3D models.
I'd like to be able to hide the individual footprints that overlap the 3D models. My original thought was to grab the bounding box of the 3D model and then use the new within style expression, but it looks like this will only filter points and lines, not polygons. The building footprint polygons have no unique information in them that I could use to filter on.
I know I could monitor map movements and query the rendered features and manually detect intersecting polygons, but since there is no unique property on the footprint, I can't filter or use feature state.
Any ideas of how to efficiently avoid rendering individual polygons in a specific area that come in from a vector tile source?
It is a common issue that the buildings layer in Mapbox Streets don't contain any unique attributes to allow filtering or rendering differently.
The best solution is usually to source a different buildings layer, and in this case, remove those redundant buildings in pre-processing.
I can think of one rather crazy workaround that might work here, although the performance may be poor.
Add the building layer with very low opacity, of type fill, essentially invisible. (Maybe invisible would work.) Call your main source buildings`.
Create a secondary building source of type geojson, and a secondary fill-extrusion layer. Call this source buildings-copy.
On map move or moveend, use querySourceFeatures to obtain a copy of all buildings.
Process this copy using Turf to remove the buildings you don't want, and call setData to set the copy as the data for buildings-copy.
You may need to do some clever caching to get reasonable performance.
I've created a base layer and 6 different overlay (Points of Interest) layers for a leaflet map.
The base layer of markers can appear on the map almost anywhere in the world, but I want the POI layers to appear only if they are in the same area (mapBounds) of the base layer. Probably the screen size.
All the data is pulled from a MySQL database and using Ajax I create the various sets of markers from two different tables, base and poi. This much is all done and working, you can see it at https://net-control.us/map2.php. The green and blue markers are from the base table, other markers are currently selected for view by clicking on the appropriate icon in the lower right. The only one active at the moment is 'Fire Station'. But if you zoom out far enough you will see additional fire stations in the Kansas City area, and in Florida. Those sets are not needed.
After the query runs I create a fitBounds variable of the base layer and another poiBounds for the poi layer. But I'm not sure I need the poiBounds. The number of base markers is generally less than 50 for the base query, but if all the poi markers are pulled world wide that number could be very large.
So I'm hoping someone can help me determine a best practice for this kind of scenario and maybe offer up an example of how it should be done. Should I...
1) Download all POIs and not worry about them appearing outside the base bounds layer? Should I inhibit them from showing in the javascript or in the SQL? How?
2) If I inhibit the unwanted points from SQL do I test one POI at a time to see if its included in the base bounds? How? Are there MySQL functions perhaps to work with this kind of data?
I'm fairly new at leaflet maps and would appreciate examples if appropriate.
2) If I inhibit the unwanted points from SQL do I test one POI at a time to see if its included in the base bounds? How? Are there MySQL functions perhaps to work with this kind of data?
You probably want a column of type POINT, a spatial index on such column (which internally is likely to be implemented as an R-Tree), and spatial relation functions on your SQL query to make use of that index.
Start by reading https://dev.mysql.com/doc/refman/8.0/en/spatial-types.html. Take your time, as spatial databases, spatial data types and spatial indices work a bit differently than their non-spatial equivalents.
I created a custom circle layer. I want to show this layer only on water and not on land. I managed to do the opposite (ie: showing the layer on land and not on water) using below command. Refer this image for better understanding
map.moveLayer('polygon','water');
Now I need to know the land layer which is used by mapboxgl so that I can call function map.moveLayer('polygon','land'); to achieve what i want.
I need help to find the different layers present in the mapboxgl-streets map. But unfortunately, Mapboxgl doesn't have map.eachLayer function.
You can use the Map#getStyle method to get a serialized representation of the entire style including the layers.
map.getStyle().layers
It depends on the map style you're using. In general, you either have to look at its source or load it in Mapbox Studio to identify the correct layer name. Also keep an eye on https://github.com/mapbox/mapbox-gl-js/issues/4173.
Just to add to Lucas' answer (which is still correct), map.getStyle().layers provides all layers in the style, including ones you have explicitly added (via map.addLayer()), and those that are included in the style (which could be a lot). Careful how you filter through these. For my case, I created arrays to hold the layers I created myself, to make future iteration simpler.
I'm following this example:
https://www.mapbox.com/mapbox-gl-js/example/multiple-geometries/
For each feature / shape on the map, they draw a new layer. However, I want to make "set" of features per Geojson I'm rendering on the map to be its own layer. Is it possible to group them somehow?
In Mapbox GL, each layer is associated with exactly one "shape" (circle, line, symbol, fill, raster, or fill-extrusion). It is not possible to render multiple "shapes" per layer.
You can control which features are rendered in a particular layer using filters.
Does that provide any more clarity? Can you describe specifically what you're trying to do?
The issue is:
I have vector/topo/image tiled maps for some places in north america which were published as ArcGIS Server REST service. These maps (A) are based in EPSG26912 projection. Now I wanna use these as basemap for my openlayer web app; besides, I also want to consume other base map sources (B), e.g., OpenStreetmap, Google Maps, ESRI, etc. Since most of these maps are in EPSG900913 which is sphericalMercator projection to my knowledge, if I just add these base map layers into openlayer map component, the group A and group B won't overlay correctly, which means they are displayed as seperate maps. I know this is something related to projection, and might need some code with proj4js, however, as a newbie, I dont really know how to start with.
Basically, I want to put OSM/Google maps as the base map for the whole world in tier 1, then put EPSG26912 base maps for some places in north america in tier 2, and put other WMS or WFS in the top tier.
do I need to transform EPSG26912 to EPSG900913 or opposite? I guess I should use EPSG900913 as the base projection.
Appreciate any replies!
Unfortunately the only solution here is to reproject data from one projection to another. Most logical would be of course to reproject EPSG:26912 to EPSG:900913.
Geoserver can help you out with this as it can reproject both WMS and WFS