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
Another possibility for when the "AR Failure" message is displayed is that one or more of the sensors on your device is not working - this may well be a temporary issue. We see this occur only rarely, but it can happen: we have observed this when trying to use the AR function in TPE immediately after booting up the device.
We have had a confirmed report from one user that this problem occurs when an external case is fitted to the phone. The case included some magnets, which are believed to cause interference with one or more internal sensors in the phone. Removing the case resolved the problem.
In another instance, the "required sensor failed" began to be shown while debugging the app and persisted for around two hours (even after a couple of device restarts) before disappearing as suddenly as it came.
If you have checked that TPE has camera permissions and are still seeing AR Failure after waiting some time, we recommend taking your device in to an Apple store to have the hardware checked over.
We've filed a suggestion with Apple to revise the "recovery suggestion" text: this problem is unrelated to privacy settings (see screenshot).
Required sensor unavailable
This is the rarest sub-species of the AR Failure beast - we've never observed it ourselves, but do very occasionally see it the logs. Our recommendation at this time is the same as for "Required sensor failed." (above).
If you encounter this error message and have any more information about recovery steps, please do get in touch and let us know.