General setup
This section will walk you through the steps to create an XR Origin camera rig for a head-mounted device and create the basic building blocks of XR interactivity.
These steps will guide you through setup to use the action-based behaviors, which is the recommended path.
Action-based vs Device-based behaviors
Several behaviors, such as the Snap Turn Provider, have two variants: an Action-based behavior and a Device-based behavior. Action-based behaviors use Actions to indirectly read input from one or more controls. Device-based behaviors use InputDevice.TryGetFeatureValue to read input directly from an InputDevice from a specific control configured on the behavior itself.
It is recommended that you use the Action-based variant instead of the Device-based variant to take advantage of the benefits that the Input System package provides. For example, it separates the logical inputs from the physical inputs, and users can create and switch between customized action maps, bind multiple cross-platform controller inputs to a single semantic action, and use event callbacks of input actions. Some features of the XR Interaction Toolkit package, such as the XR Device Simulator, are only supported when using input actions.
Import starter assets
See the Starter Assets sample for steps to import assets to streamline setup of behaviors. That sample contains a default set of input actions and presets which will be used in this guide.
Create the XR Interaction Manager
Create the XR Interaction Manager using GameObject > XR > Interaction Manager. The component on this GameObject will allow the interactors and interactables in your scenes to interact with each other.
Create the XR Origin camera rig for tracked devices
Create the XR Origin camera rig using GameObject > XR > XR Origin (Action-based).
The XR Origin component on this GameObject transforms trackable devices like the head-mounted display and controllers to their final position in the Unity scene. This is the GameObject that is moved around the environment to achieve locomotion rather than applying movement directly to the Main Camera itself.
This will also create a Camera Offset child GameObject and assign it as the value of Camera Floor Offset Object on XR Origin. This GameObject's position is updated automatically by Unity depending on the Tracking Origin Mode value on XR Origin.
For this guide, leave the Tracking Origin Mode set to Not Specified.
Note
When the mode is Device, the XR runtime will generally report the position of tracked devices relative to a fixed position in space, such as the initial position of the HMD when started. Set the Camera Y Offset on XR Origin to the height you want the Main Camera to be above ground when in that mode. When the mode is Floor, the XR runtime will generally report the position of tracked devices relative to the player's real floor. Unity will automatically clear the height of the Camera Offset when in this mode since it is not necessary to artificially raise the tracking origin up. Set the mode to Not Specified to use the default mode of the XR runtime.
If you already have a Main Camera in your scene, it will automatically move under Camera Offset as a child GameObject when using the menu to create the XR Origin. Otherwise, a new Main Camera will be created. This GameObject with the Main Camera is assigned as the value of Camera GameObject on XR Origin.
To have the position and rotation of the XR HMD update the Main Camera Transform, a Tracked Pose Driver (Input System) component is added. This component is configured to set the Position Input binding to <XRHMD>/centerEyePosition and the Rotation Input binding to <XRHMD>/centerEyeRotation.
Configure XR Controller and Interactor
An Interactor component controls how a GameObject interacts with Interactable components in the scene. There are multiple types of Interactors, one of which is an XR Ray Interactor, a component that uses ray casting in order to find valid Interactable objects in the scene.
To read input from an XR input device, the Interactor requires an XR Controller component.
Select the foldout arrows to expand the hierarchy of the XR Origin, then select the LeftHand Controller GameObject. This GameObject has an XR Controller (Action-based) component. If you do not see the Reference set for each action, click the Preset selector (the slider icon) at the top-right of the component in the Inspector window and select XRI Default Left Controller. If you do not see any presets, make sure to import starter assets. Do the same with the RightHand Controller GameObject and select the XRI Default Right Controller preset.
The table below describes the actions on the XR Controller that should be bound to an XR input device:
| Action | Required for |
|---|---|
| Position, Rotation, and Select | Basic interaction |
| Tracking State | Knowing if Position and/or Rotation inputs are valid |
| Activate | Activating a selected object |
| UI Press | Interacting with UI canvas elements |
| Haptic Device | Identifying the device to send haptic impulses to |
| Rotate and Translate Anchor | Manipulating a selected object at a distance |
The XR Controller (Action-based) component has some input action reference properties which are optional and do not need to be assigned. Refer to the property table in the documentation or refer to the tooltips in the Inspector window for more information.
The Controller and Interactor have limited support for haptic feedback. To enable haptic feedback for an XR Controller (Action-based), specify a Haptic Device Action with a binding path to an active control, such as <XRController>{LeftHand}/*. To enable haptic feedback for an XR Controller (Device-based), specify a Controller Node that supports haptic feedback, such as Left Hand. The Interactor can then specify intensities and durations of haptic feedback to play back on select and hover events, which is configured under Haptic Events in the Inspector window.
The Enable Interaction with UI GameObjects option controls whether this XR Ray Interactor can interact with Unity UI elements in a world space canvas in the scene. See UI Setup for more information and steps for enabling UI interactivity.
Enable actions for action-based behaviors
Actions must be enabled before they react to input. See Using Actions in the Input System documentation for details about this process. Action-based behaviors in this package have properties of type InputActionProperty which can either store an Action directly, or indirectly by referencing an Action contained in an Input Action Asset. Action-based behaviors automatically enable and disable the Actions that are directly defined (that is, not a reference) during their own OnEnable and OnDisable events. Action-based behaviors don't automatically enable or disable the Actions that are indirectly defined (that is, a reference) to allow the enabled state to be managed externally.
The Input Action Manager component can be used to automatically enable or disable the Actions defined in an Input Action Asset during its own OnEnable and OnDisable events.
If you created the XR Origin using GameObject > XR > XR Origin (VR), you will already have an Input Action Manager attached to the XR Origin, if not, use GameObject > Create Empty and rename the GameObject Input Action Manager. Use Component > Input > Input Action Manager to add the component to the GameObject you created.
If you have imported the Starter Assets sample package, the XRI Default Input Actions should already be set in the Action Assets configuration for the component. If Starter Assets are not available or you are creating this object manually, select Add (+) or set Size to 1 in the Inspector window to add an element to the Action Assets list. Select the element's object picker (circle icon) and choose XRI Default Input Actions.
If you later create additional Input Action Assets, add them to the Action Assets list to enable all its actions also.
Note
For Input Actions to read from input devices correctly while running in the Unity Editor, the Game view may need to have focus depending on the current project settings. If you find that your input, such as button presses on the controllers, are not working, ensure the Game view has focus by clicking it with your mouse. See Background and focus change behavior to learn how to adjust settings to not require focus in the Game view.
Create an Interactable for the player to grab
Interactable components define how the user can interact with objects in a scene. To create a basic 3D cube that can be grabbed, use GameObject > XR > Grab Interactable.
For this example, create a plane for the cube to rest on so it does not fall out of reach. Use GameObject > 3D Object > Plane, then click on the Cube and click and drag the Transform gizmo to position it above the Plane GameObject.
In the screenshot below, the GameObject with the XR Grab Interactable supports grabbing, moving, dropping, and throwing with smoothed tracking.
Tip
Interactables added through the GameObject > XR menu use a Box Collider to detect interaction, but other types of Collider components such as a convex Mesh Collider can provide better hit detection at the cost of performance.
To configure an existing GameObject to make it an interactable object to allow the user to grab it, select it in your scene and add these components:
- Add Component > XR > XR Grab Interactable
- Add Component > Physics > Box Collider
Enable an XR provider
Open Edit > Project Settings > XR Plug-in Management. If you do not yet have the package installed, click Install XR Plugin Management in that window. Select one or more of the plug-in providers for the device(s) you wish to target, such as Oculus or Open XR. Open XR will require additional configuration, see its package documentation for those steps.