# Enabling 6DoF head tracking

To enable [6DoF head tracking](https://developers.google.com/vr/discover/degrees-of-freedom) in your application, you must modify your [application manifest](https://developers.google.com/vr/reference/vr-manifest).

Applications that work in both 3DoF mode and 6DoF mode **must** declare:

    <uses-feature
     android:name="android.hardware.vr.headtracking"
     android:version="1"
     android:required="false" />

Applications that rely on 6DoF tracking for core functionality and cannot not be used without 6DoF tracking **must** declare:

    <uses-feature
     android:name="android.hardware.vr.headtracking"
     android:version="1"
     android:required="true" />

If the application works only in 3DoF, the uses-feature tag **must** be omitted.

## Performance implications

6DoF head tracking is more sensitive to application frame rate than 3DoF head
tracking. Application framerate inconsistency is also more noticeable to the
user in 6DoF. If the frame rate is too low, the application may fail the
[certification process](https://developers.google.com/vr/distribute/daydream/app-quality).

Performance recommendation:

- In 6DoF apps should target 75 FPS. Drops below 60 FPS will likely cause noticeable visual artifacts and user discomfort.