I am currently developing an app for visionOS and have encountered an issue involving a component and system that moves an entity up and down within a specific Y-axis range. The system works as expected until I introduce sound playback using AVAudioPlayer.
Whenever I use AVAudioPlayer to play sound, the entity exhibits unexpected behaviors, such as freezing or becoming unresponsive. The freezing of the entity's movement is particularly noticeable when playing the audio for the first time. After that, it becomes less noticeable, but you can still feel it, especially when the audio is played in quick succession.
Also, the issue is more noticable on real device than the simulator
//
// IssueApp.swift
// Issue
//
// Created by Zhendong Chen on 2/1/25.
//
import SwiftUI
@main
struct IssueApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
.windowStyle(.volumetric)
}
}
//
// ContentView.swift
// Issue
//
// Created by Zhendong Chen on 2/1/25.
//
import SwiftUI
import RealityKit
import RealityKitContent
struct ContentView: View {
@State var enlarge = false
var body: some View {
RealityView { content, attachments in
// Add the initial RealityKit content
if let scene = try? await Entity(named: "Scene", in: realityKitContentBundle) {
if let sphere = scene.findEntity(named: "Sphere") {
sphere.components.set(UpAndDownComponent(speed: 0.03, minY: -0.05, maxY: 0.05))
}
if let button = attachments.entity(for: "Button") {
button.position.y -= 0.3
scene.addChild(button)
}
content.add(scene)
}
} attachments: {
Attachment(id: "Button") {
VStack {
Button {
SoundManager.instance.playSound(filePath: "apple_en")
} label: {
Text("Play audio")
}
.animation(.none, value: 0)
.fontWeight(.semibold)
}
.padding()
.glassBackgroundEffect()
}
}
.onAppear {
UpAndDownSystem.registerSystem()
}
}
}
//
// SoundManager.swift
// LinguaBubble
//
// Created by Zhendong Chen on 1/14/25.
//
import Foundation
import AVFoundation
class SoundManager {
static let instance = SoundManager()
private var audioPlayer: AVAudioPlayer?
func playSound(filePath: String) {
guard let url = Bundle.main.url(forResource: filePath, withExtension: ".mp3") else { return }
do {
audioPlayer = try AVAudioPlayer(contentsOf: url)
audioPlayer?.play()
} catch let error {
print("Error playing sound. \(error.localizedDescription)")
}
}
}
//
// UpAndDownComponent+System.swift
// Issue
//
// Created by Zhendong Chen on 2/1/25.
//
import RealityKit
struct UpAndDownComponent: Component {
var speed: Float
var axis: SIMD3<Float>
var minY: Float
var maxY: Float
var direction: Float = 1.0 // 1 for up, -1 for down
var initialY: Float?
init(speed: Float = 1.0, axis: SIMD3<Float> = [0, 1, 0], minY: Float = 0.0, maxY: Float = 1.0) {
self.speed = speed
self.axis = axis
self.minY = minY
self.maxY = maxY
}
}
struct UpAndDownSystem: System {
static let query = EntityQuery(where: .has(UpAndDownComponent.self))
init(scene: RealityKit.Scene) {}
func update(context: SceneUpdateContext) {
let deltaTime = Float(context.deltaTime) // Time between frames
for entity in context.entities(matching: Self.query, updatingSystemWhen: .rendering) {
guard var component: UpAndDownComponent = entity.components[UpAndDownComponent.self] else { continue }
// Ensure we have the initial Y value set
if component.initialY == nil {
component.initialY = entity.transform.translation.y
}
// Calculate the current position
let currentY = entity.transform.translation.y
// Move the entity up or down
let newY = currentY + (component.speed * component.direction * deltaTime)
// If the entity moves out of the allowed range, reverse the direction
if newY >= component.initialY! + component.maxY {
component.direction = -1.0 // Move down
} else if newY <= component.initialY! + component.minY {
component.direction = 1.0 // Move up
}
// Apply the new position
entity.transform.translation = SIMD3<Float>(entity.transform.translation.x, newY, entity.transform.translation.z)
// Update the component with the new direction
entity.components[UpAndDownComponent.self] = component
}
}
}
Could someone help me with this?
Discuss spatial computing on Apple platforms and how to design and build an entirely new universe of apps and games for Apple Vision Pro.
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Is it possible to use a local wifi router connecting Vision Pro and Mac for developing? I tried from Unity and Xcode.
From Unity, the host app wouldn't open without WIFI (internet connection)
From Xcode, I can see the Vision Pro paired, but while try to run there's no device listed.
Any suggestions? Thanks a lot, /Ruiying
Topic:
Spatial Computing
SubTopic:
General
When I've made an animated UDSZ, at what framerate will the animation be rendered in QuickLook? Is it the same across all devices? (iPhone, Apple Vision Pro, etc.) and viewing environments? (QuickLook, inside an ARView, etc.)
Suppose I export my file at 30fps and the device draws at 60fps, does the device interpolate between frames automatically, animate at a lower frame rate, or play it at twice the speed? What if it were 24fps?
My primary concern with understanding frame rates is a bit of trouble I've had making perfectly looping animations. There always seems to be the slightest stutter between iterations.
Thanks in advance for any insights you're able to provide!
I have discovered that RemoteImmersiveSpace is limited to utilizing the structure of the CompositorContent protocol, precluding direct invocation of RealityView. Consequently, I am interested in understanding the appropriate method for integrating CompositorContent within RemoteImmersiveSpace. Thanks.
I am submitting a challenge to the Swift Student Challenge. I have created a RealityContent folder using Reality Composer Pro. How can I import this folder into the Swift Package Manager (.swiftpm) project hosted on Playground to ensure that it becomes a usable package?
Topic:
Spatial Computing
SubTopic:
Reality Composer Pro
Tags:
Swift Student Challenge
Swift Playground
RealityKit
Reality Composer Pro
Looking for help on getting "On Tap" to work inside RCP for my AVP project. I can get it to work when using "on added to scene" but if I switch to "on tap", the audio will not play when attaching the audio to an entity in my scene. I'm using the same entity for the tap gesture that the audio is using for the emitter. Here is my work flow for the "on added to scene" that works correctly to help troubleshoot my non working "on tap".
Behaviors: "on added to scene". action - timeline
Input target: check mark enabled, allowed all
Collision set to default
Audio library: source mp3 file
Chanel Audio: resource mp3 file above
Timeline: Play Audio with mp3 file added
This set up in RCP allows my AVP project to launch correctly with audio "on added to scene". But when switching behaviors to "on tap", the audio will no longer play and I can not figure out why. I've tried several different options and nothing works. Please help!
Topic:
Spatial Computing
SubTopic:
Reality Composer Pro
Tags:
Audio
USDZ
Reality Composer Pro
visionOS
Hi there,
I'm trying to merge the mesh anchor into a single mesh, but couldn't find any resources on this. Here is the code where I make the mesh from each mesh anchor, and assigned it to a model component with a shader graph material.
func run(_ sceneRec: SceneReconstructionProvider) async {
for await update in sceneRec.anchorUpdates {
switch update.event {
case .added, .updated:
// Get or create entity for this anchor
let anchorEntity = anchors[update.anchor.id] ?? {
let entity = ModelEntity()
root?.addChild(entity)
anchors[update.anchor.id] = entity
return entity
}()
// Remove any existing children
for child in anchorEntity.children {
child.removeFromParent()
}
// Generate the mesh from the anchor
guard let mesh = try? await MeshResource(from: update.anchor) else { return }
guard let shape = try? await ShapeResource.generateStaticMesh(from: update.anchor) else { continue }
print("Mesh added, vertices: \(update.anchor.geometry.vertices.count), bounds: \(mesh.bounds)")
// Get the material to use
var material: RealityKit.Material
if isMaterialLoaded, let loadedMaterial = self.shaderMaterial {
material = loadedMaterial
} else {
// Use a temporary material until the shader loads
var tempMaterial = UnlitMaterial()
tempMaterial.color = .init(tint: .purple.withAlphaComponent(0.5))
material = tempMaterial
}
await MainActor.run {
anchorEntity.components.set(ModelComponent(mesh: mesh, materials: [material]))
anchorEntity.setTransformMatrix(update.anchor.originFromAnchorTransform, relativeTo: nil)
// Add collision component with static flag - required for spatial interactions
anchorEntity.components.set(CollisionComponent(
shapes: [shape],
isStatic: true,
filter: .default
))
// Make entity interactive - enables spatial taps, drags, etc.
anchorEntity.components.set(InputTargetComponent())
let shadowComponent = GroundingShadowComponent(
castsShadow: true,
receivesShadow: true
)
anchorEntity.components.set(shadowComponent)
}
I then use a spatial tap gesture to set the position parameter in the shader graph material that creates a nice gradient from the tap position on the mesh to the rest of the mesh.
SpatialTapGesture()
.targetedToAnyEntity()
.onEnded { value in
let tappedEntity = value.entity
// Check if the tapped entity is a child of tracking.meshAnchors
if isChildOfMeshAnchors(entity: tappedEntity) {
// Get local position (in the entity's coordinate space)
let localPosition = value.location3D
// Convert to world position (scene coordinate space)
let worldPosition = value.convert(localPosition, from: .local, to: .scene)
print("Tapped mesh anchor at local position: \(localPosition)")
print("Tapped mesh anchor at world position: \(worldPosition)")
// Update the material parameter with the tap position
updateMaterialTapPosition(entity: tappedEntity, position: worldPosition)
} else {
print("Tapped entity is not a mesh anchor")
}
}
}
My issue is that because there are several mesh anchors, the gradient often gets cut off by the edge of the mesh generated from the mesh anchor as suppose to a nice continuous gradient across the entire scene reconstructed mesh I couldn't find any documentations on how to merge mesh from mesh anchors, any tips would be helpful! Thank you!
In ARKit for visionOS, I can track the user's head with a HeadAnchor, but it will not give the location. However, I can get the device's transform by calling queryDeviceAnchor(atTimestamp: CACurrentMediaTime()) on a WorldTrackingProvider.
Why the difference? - if I know the device's transform, I effectively know the head's transform.
Hi community,
I have a pair of stereo images, one for each eye. How should I render it on visionOS?
I know that for 3D videos, the AVPlayerViewController could display them in fullscreen mode. But I couldn't find any docs relating to 3D stereo images.
I guess my question can be brought up in a more general way: Is there any method that we can render different content for each eye? This could also be helpful to someone who only has sight on one eye.
I am using Entity of RealityKit to display virtual content, however I find that sometimes the real object in front of the virtual content can not occulude the virtual content.
For example, I place an Entity in a room, but when I walk into another room, I can still see the Entity through the wall.
I wonder how should I fix the problem. Thank you!
The goal is to achieve precise joint tracking for clinical assessment. The Doctor is wearing the AVP and observing the Patients movement.
Do you have any recommended best practices for integrating real-time joint tracking and displaying them on the patient within visionOS?
We attempted to use VNHumanBodyPose3DObservation, which theoretically should work, but we are unable to display the detected joints in an Immersive Space for real-time validation. This makes it difficult for the doctor to ensure accurate tracking and if possible a photo or video of the Range of Motion assessment would be needed for the patient record.
Are there alternative methods to achieve precise real-time joint tracking without requiring main camera access (com.apple.developer.arkit.main-camera-access.allow)?
I have been using ARKit to get hand tracking data on a continuous loop by implementing the AnchorUpdateSequence.
I want to try out the .predicted hand tracking, but it seems as though using ARKit session and HandTrackingProvider do not allow me to enable this feature?
Hello, I'm adding a CollisionComponent to an entity in RealityView. CollisionComponent requires that a Mesh must be provided as a reference for collision detection. However, in order to achieve more accurate detection, I hope that this Mesh resource is a geometric shape of a USDZ model. Is there any way to make it happen? Thank you!
I was trying to use a local Wifi router to connect Vision Pro and Mac for developing. From Unity, the host on Vision Pro wouldn't open; from Xcode I can see vision pro paired but by the Run button there's no device listed...thanks any ideas? /Ruiying
Topic:
Spatial Computing
SubTopic:
General
Hey there,
since SceneView has been marked as „deprecated“ for SwiftUI, I‘m wondering which alternatives should be considered for the following situation:
I have a SwiftUI app (for iOS and iPadOS) where users can view (with rotate, scale, move gestures) 3D models (USDZ) in a scene. The models will be downloaded from web backend and called via local URL paths.
What I tested:
I‘ve tried ARView in .nonAR mode, RealityView, however I didn‘t get the expected response -> User can rotate, scale the 3D models in a virtual space.
ARView in nonAR mode still shows the object like in normal AR mode without camera stream.
I tried to add Gestures to the RealityView on iOS - loading USDZ 3D models worked but the gestures didn’t).
Model3D is only available for visionOS (that would be amazing to have it for iOS)
I also checked QuickLook Preview however it works pretty strange via Filepicker etc, which is not the way how the user should load the 3D models in my app.
Maybe I missed something, I couldn’t find anything which can help me. I‘m pretty much stucked adopting the latest and greatest frameworks/APIs in my App and taking the next steps porting my app to visionOS.
Long story short 😃:
Does someone have an idea what is the alternative to SceneView for USDZ 3D models?
I appreciate your support!!
Thanks in advance!
HoverEffectComponent on macOS 15 and iOS 18 works fine using RealityView, but seems to be ignored when ARView (even with a SwiftUI UIViewRepresentable) is used.
Feedback ID: FB15080805
Hi,
We are trying to port our Unity app from other XR devices to Vision Pro. Thus it's way easier for us to use the Metal rendering layer, fully immersive. And to stay true to the platform, we want to keep the gaze/pinch interaction system.
But we just noticed that, unlike Polyspatial XR apps, VisionOS XR in Metal does not provide gaze info unless the user is actively pinching... Which forbids any attempt to give visual feedback on what they are looking at (buttons, etc).
Is this planned in Apple's roadmap ?
Thanks
Reality Composer is no longer available in XCode 15 Release. Is this intended or will be available in later releases? Do I need to revert to Xcode15 Beta8 to get Reality Composer?
my coworkers and i are guessing at what data defines an anchor. i tried searching but struggled to find anything helpful.
our best guess was a combination Triangular Irregular Networks (TIN), gps, magnetic compass direction and maybe elevation sensors.
is this documented anywhere? if not, can a definition or description be provided?
Hi
I try to make a 360 stereo viewer, and I have made a ShaderGraphMaterial on Reality Composer Pro.
Im trying to use that material on a inverted sphere whitch is generated in Swift.
When I try to attach the material I get this error "Type of expression is ambiguous without a type annotation"
Here is the code (sorry im noob =) ):
import SwiftUI
import RealityKit
import RealityKitContent
import PhotosUI
struct ImmersiveView: View {
@Environment(AppModel.self) var appModel
var body: some View {
RealityView { content in
// Add the initial RealityKit content
guard let skyBoxEntity = await createSkybox() else {
return
}
content.add(skyBoxEntity)
}
}
}
private func createSkybox () async -> Entity? {
var matX = try? await ShaderGraphMaterial(named:
"/Root/Mat_Stereo360",
from: "360Stereo.usda",
in: realityKitContentBundle)
let sphere = await MeshResource.generateSphere(radius:1000)
let entity = await Entity()
entity.components.set(ModelComponent(mesh: sphere, materials:
[matX])). //ERROR HERE:
Type of expression is ambiguous without a type annotation
//entity.scale *= .init(x:-1, y:1, z:1)
return entity
}
I hope someone can help me =)
Best regards,
Kim