Anchor content at real world locations

Applicable XR devices

This guidance helps you build experiences for these types of XR devices.

Learn about XR device types →

Learn about XR device types →

Geospatial anchors are a type of anchor that allow you to place 3D content with geographical coordinates using the Geospatial API.

Geospatial anchors use a latitude and longitude to determine their positioning. The latitude and longitude are defined by the WGS84 specification, which are the same coordinates shown in a typical GPS system.

Determine the latitude and longitude of a location

If you have a specific point of interest in mind, use Google Maps to determine its latitude and longitude:

1. Go to Google Maps on a desktop computer.

2. Navigate to Layers > More.

   

   

3. Change the Map Type to Satellite and clear the Globe View checkbox at the bottom left corner of the screen.

   

   This forces a 2D perspective and eliminates possible errors that can come from an angled 3D view.

4. On the map, right-click the location and select the longitude and latitude to copy it to your clipboard.

Convert a position in the user's area to a Geospatial anchor

If you are able to travel to the point of interest, you can determine the latitude, longitude, and altitude from a local reading by converting a device-local pose to a Geospatial pose.

Position content at a Geospatial anchor

Geospatial anchors require an altitude value, which is relative to the WGS84 ellipsoid or relative to the terrain or rooftop.

• For altitude values relative to the WGS84 ellipsoid, use Geospatial.createAnchor:

  val createAnchorResult = geospatial.createAnchor(
      latitude,
      longitude,
      altitude,
      Quaternion.Identity,
  )
  GeospatialAnchor.kt

• For altitude values relative to the terrain or a rooftop, use Geospatial.createAnchorOnSurface, using GeospatialSurface.TERRAIN and GeospatialSurface.ROOFTOP respectively to specify how the final altitude should be interpreted:

  val createAnchorResult = geospatial.createAnchorOnSurface(
      latitude,
      longitude,
      altitude,
      Quaternion.Identity,
      GeospatialSurface.TERRAIN,
  )
  GeospatialAnchor.kt

  When using GeospatialSurface.ROOFTOP, the altitude defaults to the terrain altitude when not placed on a building.

Then, check the result of the creation call:

when (createAnchorResult) {
    is AnchorCreateSuccess -> {
        // Use anchorCreateResult.anchor to render content at the result.
    }

    else -> {
        // Anchor create failed.
        // See AnchorCreateResult for possible failure reasons.
    }
}
GeospatialAnchor.kt

Finally, use the anchor to position 3D content:

Subspace(FollowTarget.anchor(anchorCreateResult.anchor)) {
    SpatialPanel {
        GeospatialContent()
    }
}
GeospatialAnchor.kt

val anchorSpace = AnchorSpace.create(session, anchorCreateResult.anchor)
val contentEntity = createGeospatialContentEntity(context, session)
anchorSpace.addChild(contentEntity)
GeospatialAnchor.kt