# XRTrackableFeature

This OpenXRInteractionFeature configures new extension `XR_ANDROID_trackables` at runtime and provides XRPlaneSubsystem implementation that works on Android XR platform.

Note: due to the dependency on [XRSessionFeature](https://developer.android.com/develop/xr/unity/reference/class/Google/XR/Extensions/XRSessionFeature#classGoogle_1_1XR_1_1Extensions_1_1XRSessionFeature), its priority must be lower than session feature so the feature registration happens after XrInstanceManager creation.

## Summary

### Inheritance

Inherits from: `OpenXRFeature`

|                                                                                                                                            ### Public attributes                                                                                                                                             ||
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------|
| [ExtensionString](https://developer.android.com/develop/xr/unity/reference/class/Google/XR/Extensions/XRTrackableFeature#extensionstring)` = "XR_ANDROID_trackables"`   | `const string` The OpenXR Extension string.                                                                                         |
| [FeatureId](https://developer.android.com/develop/xr/unity/reference/class/Google/XR/Extensions/XRTrackableFeature#featureid)` = "com.google.xr.extensions.trackables"` | `const string` The feature ID string.                                                                                               |
| [UiName](https://developer.android.com/develop/xr/unity/reference/class/Google/XR/Extensions/XRTrackableFeature#uiname)` = "Android XR (Extensions): Plane"`            | `const string` The UI name shows on the XR Plug-in Management panel, help users to understand validation errors and expected fixes. |

|                                                                                                                                                                                        ### Public static attributes                                                                                                                                                                                        ||
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [IsExtensionEnabled](https://developer.android.com/develop/xr/unity/reference/class/Google/XR/Extensions/XRTrackableFeature#isextensionenabled)` => _extensionEnabled`                           | `bool` Gets if the required OpenXR extension is enabled.                                                                                                                                                 |
| [RequiredPermission](https://developer.android.com/develop/xr/unity/reference/class/Google/XR/Extensions/XRTrackableFeature#requiredpermission)` = AndroidXRPermission.SceneUnderstandingCoarse` | `readonly `[AndroidXRPermission](https://developer.android.com/develop/xr/unity/reference/namespace/Google/XR/Extensions#androidxrpermission) Runtime permission required to enable scene understanding. |

## Public attributes

### ExtensionString

```c#
const string ExtensionString = "XR_ANDROID_trackables"
```  
The OpenXR Extension string.

Used to check if this extensions is available or enabled.  

### FeatureId

```c#
const string FeatureId = "com.google.xr.extensions.trackables"
```  
The feature ID string.  

### UiName

```c#
const string UiName = "Android XR (Extensions): Plane"
```  
The UI name shows on the XR Plug-in Management panel, help users to understand validation errors and expected fixes.

## Public static attributes

### IsExtensionEnabled

```c#
bool IsExtensionEnabled => _extensionEnabled
```  
Gets if the required OpenXR extension is enabled.

When OpenXR runtime is waiting, it returns `null`. Otherwise, it indicates whether the XR_ANDROID_trackables extension is available on current device.  

### RequiredPermission

```c#
readonly AndroidXRPermission RequiredPermission =
            AndroidXRPermission.SceneUnderstandingCoarse
```  
Runtime permission required to enable scene understanding.