# TrackData

Data that was recorded to an external `https://developers.google.com/ar/reference/unity-arf/struct/Google/XR/ARCoreExtensions/Track#structGoogle_1_1XR_1_1ARCoreExtensions_1_1Track`.

Obtained by `https://developers.google.com/ar/reference/unity-arf/class/Google/XR/ARCoreExtensions/ARPlaybackManager#getupdatedtrackdata`.

## Summary

| ### Public attributes ||
|---|---|
| `https://developers.google.com/ar/reference/unity-arf/struct/Google/XR/ARCoreExtensions/TrackData#data` | `byte[]` The byte data array that was recorded via `https://developers.google.com/ar/reference/unity-arf/class/Google/XR/ARCoreExtensions/ARRecordingManager#recordtrackdata`. |
| `https://developers.google.com/ar/reference/unity-arf/struct/Google/XR/ARCoreExtensions/TrackData#frametimestamp` | `long` The timestamp in nanoseconds of the frame the given `https://developers.google.com/ar/reference/unity-arf/struct/Google/XR/ARCoreExtensions/TrackData#structGoogle_1_1XR_1_1ARCoreExtensions_1_1TrackData` was recorded on. |

## Public attributes

### Data

```c#
byte[] Google::XR::ARCoreExtensions::TrackData::Data
```
The byte data array that was recorded via `https://developers.google.com/ar/reference/unity-arf/class/Google/XR/ARCoreExtensions/ARRecordingManager#recordtrackdata`.

### FrameTimestamp

```c#
long Google::XR::ARCoreExtensions::TrackData::FrameTimestamp
```
The timestamp in nanoseconds of the frame the given `https://developers.google.com/ar/reference/unity-arf/struct/Google/XR/ARCoreExtensions/TrackData#structGoogle_1_1XR_1_1ARCoreExtensions_1_1TrackData` was recorded on.

If frames are skipped during playback, the played back external track data may be attached to a later frame. This timestamp is equal to the result of `https://docs.unity3d.com/Packages/com.unity.xr.arsubsystems@4.2/api/UnityEngine.XR.ARSubsystems.XRCameraFrame.html#UnityEngine_XR_ARSubsystems_XRCameraFrame_timestampNs` on the frame during which track data was written.