Gestures

Add new gestures to your RealityKit entities without worrying about adding your own gesture recognisers.

Turn

RealityKit offers a 2 finger rotate gesture, but it can be a little awkward to use two fingers on a phone while looking at something in AR. HasTurnTouch adds a way to rotate something in any axis you like with just one finger.

The entity with the touch needs to use the HasTurnTouch protocol, then simply set the turnAxis to be the angle to rotate around and set the collision component (used for starting the initial collision).

For this gesture you need to have also run RealityUI.enableGestures(.longTouch, on: arView) at least once on your ARView.

See the documentation here.

Example

Example Entity class:

class KeyModel: Entity, HasTurnTouch, HasModel {
  init(with model: ModelComponent) {
    self.turnAxis = [0, 0, -1]
    self.collision = CollisionComponent(shapes: [.generateBox(size: [1, 1, 0.2])])
    self.model = model
  }
}

Adding the class that uses HasTurnTouch:

// IMPORTANT: Required to enable RealityUI long touch gestures
// Only needs to be called once per ARView.
RealityUI.enableGestures(.longTouch, on: arView)

let testAnchor = AnchorEntity(world: [0, 0, -1])
testAnchor.addChild(KeyModel(with: keyModel))

arView.scene.addAnchor(testAnchor)

Tap

Let RealityUI easily take care of the raycasting to find where any taps on your ARView end up in your RealityKit scenes with HasClick.

For this gesture you need to have also run RealityUI.enableGestures(.tap, on: arView) at least once on your ARView.

See the documentation here.

/// Example class that uses the HasClick protocol
class ClickyEntity: Entity, HasClick, HasModel {
  // Required property from HasClick
  var tapAction: ((HasClick, SIMD3<Float>?) -> Void)?

  init(model: ModelComponent, tapAction: ((HasClick, SIMD3<Float>?) -> Void)) {
    self.tapAction = tapAction
    super.init()
    self.model = model
    self.generateCollisionShapes(recursive: false)
  }

  required convenience init() {
     self.init()
  }
}

Adding to your RealityKit scene:

// IMPORTANT: Required to enable RealityUI tap gesture
// Only needs to be called once per ARView.
RealityUI.enableGestures(.tap, on: arView)

let testAnchor = AnchorEntity(world: [0, 0, -1])

let clickySphere = ClickyEntity(
  model: ModelComponent(mesh: .generateBox(size: 0.2), materials: [SimpleMaterial(color: .red, isMetallic: false)])
) { (clickedObj, atPosition) in
    // In this example we're just assigning the colour of the clickable
    // entity model to a green SimpleMaterial.
    (clickedObj as? HasModel)?.model?.materials = [
        SimpleMaterial(color: .green, isMetallic: false)
    ]
}

testAnchor.addChild(clickySphere)
arView.scene.addAnchor(testAnchor)