CRS:84 Projection TileLayer?

[jfuehner]

Recently made the switch from using the Mapbox.gl/deck.gl combination to a pure deck implementation. I was previously using Mapbox purely for base maps/raster tile rendering from ArcGIS WMS services.

I am now connecting to ArcGIS WMS services using the deck TileLayer. The getTileData function is requesting tiles using the CRS:84 projection. With that said, I have noticed that when I am at max zoom and have some entities added to the map they appear not where they should be.

When I start zooming in and the WMS tiles start rendering for the closer zoom level(s) the tiles and the entities start syncing/displaying at the expected position.

Previously, I was using Mapbox with the older EPSG:3857 projection which was rendering points at the higher zoom levels fine.

Could this be an issue with the service and how the imagery was published for tiles at the higher scale for CRS:84? Or is there perhaps something I should be considering on the deck side?

Any thoughts, suggestions or even speculations would be appreciated...

[kylebarron]

The getTileData function is requesting tiles using the CRS:84 projection

I don't think the TileLayer currently supports the global geodetic tiling system, because it expects to display them in the OSM indexing system with Web Mercator coordinates. You'd need to overwrite your own Tileset2D class https://github.com/visgl/deck.gl/blob/master/modules/geo-layers/src/tile-layer/tileset-2d.js

[kylebarron]

We should probably make it easier to swap in another tileset2D class, so that you could make a custom subclass of tileset easily. Would you accept a PR @Pessimistress, should tileset2D be a prop to the layer that could be overwritten?

[jfuehner]

@kylebarron I also experience the same issue when requesting tiles with the EPSG:4326 projection as well so it does not appear to be limited to CRS:84.

[kylebarron]

CRS:84 and EPSG:4326 are the same thing https://gis.stackexchange.com/a/54083

The TileLayer currently only works with the Web Mercator projection (EPSG:3857)

[Pessimistress]

In 8.4.0-beta there is a new _imageCoordinateSystem prop on the BitmapLayer.

[kylebarron]

That's true, but the TileLayer still only handles indexing in Web Mercator coordinates. So it won't locate and load tiles in other indexing systems correctly. My interpretation of the original question is to load tiles in the "global geodetic tiling system", where coordinates are in WGS84. In that indexing system, there's two tiles at zoom 0, one for each half of the globe, and then a quadtree within each half at each zoom level.

I don't expect that deck.gl support every indexing system natively, but it would be nice for advanced users to easily swap in another tileset. Right now that's not possible because Tileset2D isn't exported.

import {Tileset2D, TileLayer} from '@deck.gl/geo-layers';

class MyTileset2D extends Tileset2D {
  // overwrite getTileIndices
}

new TileLayer({
  tileset2d: MyTileset2D
})