I made the code as simple as possible: a single 5cm target square placed at location (0, 0, -1.5)
I then tapped on target while standing in several locations, and the reported tap location was off along the Z axis by about 0.5m.
Here were several tap locations (Z location is underlined):
tap location: SIMD3(0.0067811073, 0.019996116, -1.1157947), name: target
tap location: SIMD3(-0.00097223074, 0.019996116, -1.1036792), name: target
tap location: SIMD3(0.0008024718, 0.019995179, -1.1074299), name: target
tap location: SIMD3(-0.009804221, 0.019996116, -1.0694565), name: target
tap location: SIMD3(-0.0037206858, 0.019995492, -1.0778457), name: target
tap location: SIMD3(-0.009298846, 0.019996116, -1.0772702), name: target
Here is the code to set up the RealityView:
import SwiftUI
import RealityKit
import RealityKitContent
struct ImmersiveView: View {
@StateObject var model = MyModel()
/// Spatial tap gesture that tells the model the tap location.
var myTapGesture: some Gesture {
SpatialTapGesture()
.targetedToAnyEntity()
.onEnded { event in
let location3D = event.convert(event.location3D, from: .global, to: .scene)
let entity = event.entity
model.handleTap(location: location3D, entity: entity)
}
}
var body: some View {
RealityView { content in
model.setupContentEntity(content: content)
}
.gesture(myTapGesture)
}
}
Here is the model code:
import Foundation
import SwiftUI
import RealityKit
import RealityKitContent
import ARKit
import os.log
@MainActor class MyModel: ObservableObject {
private var realityViewContent: RealityViewContent?
/// Capture RealityViewContent and create target
///
/// - Parameter content: container for all RealityView content
func setupContentEntity(content: RealityViewContent) {
self.realityViewContent = content
placeTargetObject()
}
/// Place a small red target at position 0, 0, -1.5
///
/// I will look at this position and tap my fingers. The tap location
/// should be near the same position (0, 0, -1.5)
func placeTargetObject() {
guard let realityViewContent else { return }
let width: Float = 0.05
let height: Float = 0.02
let x: Float = 0
let y: Float = 0
let z: Float = -1.5
// Create red target square
let material = SimpleMaterial(color: .red, isMetallic: false)
let mesh = MeshResource.generateBox(width: width, height: height, depth: width)
let target = ModelEntity(mesh: mesh, materials: [material])
// Add collision and target component to make it tappable
let shapeBox = ShapeResource.generateBox(width: width, height: height, depth: width)
let collision = CollisionComponent(shapes: [shapeBox], isStatic: true)
target.collision = collision
target.components.set(InputTargetComponent())
// Set name, position, and add it to scene
target.name = "target"
target.setPosition(SIMD3<Float>(x,y + height/2, z), relativeTo: nil)
realityViewContent.add(target)
}
/// Respond to the user tapping on an object by printing name of entity and tap location
///
/// - Parameters:
/// - location: location of tap gesture
/// - entity: entity that was tapped
func handleTap(location: SIMD3<Float>, entity: Entity) {
os_log("tap location: \(location), name: \(entity.name, privacy: .public)")
}
}
Example of the small red target:
