AR Interaction Overview

This page provides a brief explanation for setting up a scene for mobile touchscreen AR and the related components.

Note

AR interaction components are only available in a Project that also includes the AR Foundation package. You can install the AR Foundation package via the Package Manager.

Touchscreen gestures

Touchscreen gesture data is surfaced by the TouchscreenGestureInputController which translates touch events into gestures such as tap, drag, pinch and twist. This gesture data can be used as bindings for Input System actions.

The XR Interaction Toolkit package comes with a number of pre-defined gestures and gesture interactables, but you can always extend this package by defining your own gestures.

Gesture	Triggered by input
Tap	User touches the screen
Drag	User drags finger across screen
Pinch	User moves two fingers toward or away from each other along a straight line
Twist	User rotates two fingers around a center point
Two Finger Drag	User drags with two fingers

Setting up for Touchscreen AR

Note

The AR Starter Assets sample contains an already configured input action map which can be used in place of creating one from scratch.

To set up a scene for Touchscreen AR you will want to create an Input Action Map with action bindings to the TouchscreenGestureInputController gesture data. (An action map asset can be created by right-clicking on the Assets folder and going to Create > Input Actions.)

Note

The AR Starter Assets sample contains a screen-space controller preset, but if creating the controller from scratch, follow the instructions below.

Add an XR Screen Space Controller to the scene and toggle Enable Touchscreen Gesture Input Control. This will ensure that a TouchscreenGestureInputController device gets added to the scene. Additionally, make sure to include an XR Ray Interactor and that Enable AR Raycasting is checked.

Connect the input actions to the appropriate properties on the screen space controller. The application should now be ready to receive touchscreen input.

AR Transformer

In order to have interactables adhere to the AR environment, adding an ARTransformer is necessary. The AR transformer allows objects to be moved and rotated only within the limits of the AR environment. Currently, only AR planes are supported.

AR Starter Assets

A configured scene for touchscreen AR is available in the AR Starter Assets sample which is installable through the Samples tab under the XR Interaction Toolkit package in the Package Manager window.

This scene includes key mappings to simulate gestures in-editor. The following are keys to note:

• 'E' and 'R' rotate the object around the up axis.
• 'Z', 'X' and the scroll wheel scale the object up and down.