Use the device's flash unit on Android SDK (Kotlin/Java)

  • You can enable the device's flash unit during an AR session to improve visibility.

  • Before enabling the flash, check if the current camera configuration supports it using CameraCharacteristics.FLASH_INFO_AVAILABLE.

  • Enable the flash unit by configuring the AR session with Config.FlashMode.TORCH.

  • Disable the flash unit by configuring the AR session with Config.FlashMode.OFF.

Enabling the device's flash unit during an AR session can help improve visibility.

Check that the current camera configuration supports flash

Not all camera configurations support enabling a flash unit. Before enabling the flash or offering users the option to enable the flash, ensure that the flash unit is available for the active camera configuration:

Java

boolean flashAvailable;
try {
  CameraManager cameraManager =
      (CameraManager) context.getSystemService(Context.CAMERA_SERVICE);

  CameraCharacteristics characteristics =
      cameraManager.getCameraCharacteristics(session.getCameraConfig().getCameraId());
  flashAvailable = characteristics.get(CameraCharacteristics.FLASH_INFO_AVAILABLE);
} catch (Exception e) {
  flashAvailable = false;
}

Kotlin

val flashAvailable =
  runCatching {
      val cameraManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager
      val characteristics = cameraManager.getCameraCharacteristics(session.cameraConfig.cameraId)
      characteristics.get(CameraCharacteristics.FLASH_INFO_AVAILABLE)
    }
    .getOrNull() ?: false

Enable the flash unit

Enable the flash unit by configuring the AR session with Config.FlashMode.TORCH:

Java

if (flashAvailable) {
  Config config = session.getConfig();
  config.setFlashMode(Config.FlashMode.TORCH);
  session.configure(config);
}

Kotlin

if (flashAvailable) {
  session.configure(session.config.apply { flashMode = Config.FlashMode.TORCH })
}

Disable the flash unit

Disable the flash unit by configuring the AR session with Config.FlashMode.OFF:

Java

Config config = session.getConfig();
config.setFlashMode(Config.FlashMode.OFF);
session.configure(config);

Kotlin

session.configure(session.config.apply { flashMode = Config.FlashMode.OFF })