Enable the Geospatial API for your Android NDK app (C)

Configure your app's settings so that it can use the Geospatial API.

Prerequisites

Make sure that you understand fundamental AR concepts and how to configure an ARCore session before proceeding.

If you want to run a sample app that demonstrates the functionality described here, see the ARCore Geospatial Quickstart for Android for Java. The sample app in the Quickstart is written in Java. The code samples in this document are for the same functionality written in C.

See the Introduction to the Geospatial API for more information about the Geospatial API.

If you're new to developing with ARCore, see Getting started for information about software and hardware requirements, prerequisities and other information specific to the platforms you are using.

Be sure your development environment satisfies the ARCore SDK requirements, as described in the Quickstart for Java.

Enable the ARCore API

Before using the Visual Positioning System (VPS) in your app, you must first enable the ARCore API in a new or existing Google Cloud project. This service is responsible for hosting, storing, and resolving Geospatial anchors.

Keyless authorization is preferred, but API Key authorization is also supported.

Add required libraries to your app

After authorizing your app to call the ARCore API, you must add libraries to enable Geospatial features in your app.

In your app's build.gradle file, setup Google Play services to include the Play Services Location library.

dependencies {
  // Apps must declare play-services-location version >= 16.
  // In the following line, substitute `16 (or later)` with the latest version.
  implementation 'com.google.android.gms:play-services-location:16 (or later)'
}

Enable Geospatial capabilities in the session configuration

Before creating the session, change the GeospatialMode in your session configuration to ENABLED:

// Create a session config.
ArConfig* ar_config = NULL;
ArConfig_create(ar_session, &ar_config);

// Enable the Geospatial API.
ArConfig_setGeospatialMode(ar_session, ar_config, AR_GEOSPATIAL_MODE_ENABLED);
CHECK(ArSession_configure(ar_session, ar_config) == AR_SUCCESS);

// Release config resources.
ArConfig_destroy(ar_config);

While the Geospatial mode is set to ENABLED, the application is allowed to obtain geographical information from the Visual Positioning System (VPS).

Prompt user to allow usage of device data

Apps that use the ARCore Geospatial API must present the user with a prompt to acknowledge and allow the use of data from their device. See User privacy requirements for more information.

Check device compatibility

Not all devices that support ARCore also support the Geospatial API, as described in the quickstart for Java.

To check the user's device for compatibility, call ArSession_isGeospatialModeSupported(). If this returns false do not attempt to configure the session (below), as doing so will cause the ArStatus to report an AR_ERROR_UNSUPPORTED_CONFIGURATION.

Ask user for location permissions at runtime

Your app must request location permissions at runtime.

To use the ARCore Geospatial API, your app needs to register the following extra permissions:

  • ACCESS_FINE_LOCATION to accurately determine the user's location.

  • ACCESS_COARSE_LOCATION for non-accurate determination of the user's location and to comply with user privacy requirements. However, the Geospatial API cannot be configured to work with coarse location, and API requests will fail when the user has set this permission. See below for more information.

  • ACCESS_INTERNET to contact the ARCore Geospatial API service.

<manifest ... >
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
  <uses-permission android:name="android.permission.INTERNET" />
</manifest>

On devices that run Android version 12 or higher, users can request that your app have access to only approximate location information. To accommodate this request, your app must have the ACCESS_COARSE_LOCATION permission configured, along with ACCESS_FINE_LOCATION, as shown above. You must configure both location permissions.

However, when users specify coarse location, doing so prevents the Geospatial API from obtaining the precise location it requires. The Geospatial service will not allow itself to be configured if your app gives it only coarse location. Your app cannot use the Geospatial API with coarse location.

Check Geospatial availability at the device's current location

Because the Geospatial API uses a combination of VPS and GPS to determine a Geospatial pose, the API can be used as long as the device is able to determine its location. In areas with low GPS accuracy, such as indoor spaces and dense urban environments, the API will rely on VPS coverage to generate high accuracy poses. Under typical conditions, VPS can be expected to provide positional accuracy of approximately 5 meters, and rotational accuracy of 5 degrees. Use ArSession_checkVpsAvailabilityAsync() to determine if a given location has VPS coverage.

The Geospatial API can also be used in areas that do not have VPS coverage. In outdoor environments with few or no overhead obstructions, GPS may be sufficient to generate a pose with high accuracy.

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