If, when you try to access Augmented Reality in TPE for iOS you see the message "AR Failure", there are two possibilities:
- You have revoked permission for TPE to use your device's camera
- One or more of the required sensors in your device has failed or is unavailable (camera video feed, GPS, accelerometer, gyroscope, compass)
Camera Access Not Authorized
In TPE 4.1.4 or later, you'll a message similar to this, explaining the failure and recommending steps to resolve it:
In earlier versions (4.0 - 4.1.3), you will see a mostly blank screen with the words "AR Failure":
Check that TPE has permission to access the device's camera. This is required in order to use the AR function. You will be asked for permission to access the camera when you first use the AR function. If you do not grant permission, AR will not work. If you subsequently revoke permission to use the camera, AR will stop working.
In TPE 4.1.4 or later, clicking the Settings button in the Alert that is shown (above) will take you directly to the dedicated iOS Settings page for TPE, where you can grant camera permission:
If you need to find the permission manually, you can do so as follows. In iOS Settings, go to Privacy -> Camera. Ensure that TPE is enabled to access the camera, as shown:
Required Sensor Failed
The other possibility for seeing the "AR Failure" message is that one or more of the sensors on your device is not working. We see this occur only rarely, but it can happen.
If you have checked that TPE has camera permissions and are still seeing AR Failure, we recommend taking your device in to an Apple store to have the hardware checked over.
Update, 26 Jan 2018
You always learn something interesting while using an app out and about in the field. Today, I had just rebooted my phone and started up TPE, switching immediately to use AR, and saw this:
While I'd noticed this error cropping up in the logs occasionally, I'd never actually experienced it before. What was interesting about this was the timing: I suspect it is related to trying to use AR before the device has had a chance to start all the internal sensors required. I tapped back to the map and back to AR a few seconds later and all was well.
We've filed a suggestion with Apple to revise the "recovery suggestion" text: this problem is unrelated to privacy settings (see screenshot).