# Interaction Components
# Interaction Prefab
The Interaction prefab included when importing the Snapdragon Spaces Samples contains three prefabs for the different interaction methods supported by the samples.
The Interaction Manager component is in the root GameObject of this prefab. It contains the methods for the different interaction input modalities as well as the code that handles input interaction switching.
For AR Devices, the default configuration will start with Hand Tracking and fallback to the Gaze Pointer if the QCHT package is not included in the Unity project or if Hand Tracking is not compatible with the target device. Otherwise it will switch from Hand Tracking > Gaze Pointer > Device Input.
For VR/MR Devices, if a controller is tracked, it will automatically start with XR Controllers as the default input modality. Otherwise it will start with Hand Tracking as the default input modality. The Automatic Controller Switch component in the Interaction prefab detects the controller tracked status and automatically disables Hand Tracking when a controller is tracked or enables Hand Tracking when there are no controllers tracked. The user can switch between XR Controllers/Hand Tracking and Gaze Pointer input modality pressing the Menu button on the left Controller.
Hand Tracking
Refer to QCHT Hand Tracking for related documentation.
# XR Interaction Manager
At least one XR Interaction Manager is required per scene in order to establish a connection between the Interactors and Interactables.
Input Actions must be enabled through the Input Action Manager. To add them manually, locate the Input Action Manager script and add an Input Action asset as an element. These assets are located in the samples path under Shared Assets > Input Actions.
# Gaze Pointer
The Gaze Pointer is comprised of the following GameObjects:
The Gaze Interaction UI component is added to the XR Gaze Interactor GameObject. It manages the interaction with the XR Gaze Interactor (opens new window) component with UI objects in the scene as well as the timer duration and "click" functionality of the pointer.
GAZE POINTER LIMITATIONS
Currently the gaze pointer can only interact with UI objects in the scene with a XR Simple Interactable (opens new window) component, unlike the Pointer Controller, which can interact with both UI and 3D objects.
The XR Gaze Interactor also has a Spaces Composition Layer component. See Unity Gaze Pointer Composition Layer Sample for documentation about using composition layers to render view locked content.
# Controller Manager
The Controller Manager is comprised of the following GameObjects:
On the root GameObject, the XR Controller Manager component receives the XRControllerProfile from the Interaction Manager component. If the Host Controller is being used, the Device Pointer will be activated. The Device Pointer contains the Host Controller mesh and input references. If a VR device with two controllers is being used, the XR Controllers GameObject will be activated. The XR Controllers prefab contains two GameObjects for the left and right controller with an Action Based Controller (opens new window) component with references to each controller prefab and the specific input references.
The Interaction Manager will send the selected XRControllerProfile to the XR Controller Manager based on what InputDevice (opens new window) is being used. Please refer to the Unity documentation for Microsoft Mixed Reality Motion Controller Profile (opens new window) or Oculus Touch Controller Profile (opens new window).
# Input Cheat Sheet
Buttons used for input actions:
| Host Controller | XR Controller Right | XR Controller Left | |
|---|---|---|---|
| Select | Tap on Trackpad | Right Trigger Button | Left Trigger Button |
| Gaze/Pointer switch | Menu Button | None | Left Menu Button |
| Touchpad | Trackpad | Right Joystick | Left Joystick |
| Anchor Position Confirmation | Tap on Trackpad | Any Trigger Button | Any Trigger Button |
# Controller Haptics
Controller haptics are sent via the Interaction Manager's SendHapticImpulse (opens new window) function to the XR Controller Manager. When SendHapticImpulse is called, a haptic impulse is triggered on both the Host Controller and XR Controllers on UI button press or when scrolling.
WARNING
Haptic feedback is felt on both XR controllers at the moment, regardless of which one triggers an action.
# Controller Animations for XR Controllers
Each XR Controller in XRControllers has a reference to their XR Controller prefab containing the controller mesh with the buttons' blend shapes.
Each prefab has an XR Controller Input Animation attached. This script will update the blend shape weight (opens new window) values with the values received of each button of the controller, creating the button animations.
# Editor Camera Controller
While build times can be quite time consuming, the editor camera controller allows for quick testing within the Unity editor itself and provides a key shortcut to switch between the gaze pointer and the controller. The key to switch is output in the Editor console.
TIP
XR Device Simulator (opens new window) is also compatible with the Snapdragon Spaces samples for Editor simulation of interactions.
# Spaces Hand Tracking Button Binding
Each button, toggle or slider prefab has an Spaces Hand Tracking Button Binding wrapper in the samples to disable unnecessary XR Simple Interactable components and Snapping Volumes for other interaction methods than Hand Tracking.
# Interaction Packages
The Snapdragon Spaces plugin works great with a number of interaction packages. Please refer to the specific pages for details on how to get started with those: