My visionOS 26.3 app displays a diorama-like scene in a RealityView in a mixed immersive space, about 1 meter square, with view attachments floating above the scene.
Each view attachment fades out after user interaction, by animating the view's opacity.
What I'm observing is that depending on the position of a view attachment relative to the scene and the camera, an unwanted cutout effect is observed (presumably because of draw order issues), as shown in the right column in the screenshots below.
YouTube video link of these sequences: https://youtu.be/oTuo0okKCkc
(19 seconds)
My question:
How does visionOS determine the view attachment draw order relative to the RealityView scene?
If I better understood how the draw order is determined, I could modify my scene to ensure that the view attachments were always drawn after the scene, fixing the unwanted cutout effect.
I've successfully used ModelSortGroupComponent to control the draw order of entities within the RealityView scene, but my understanding is that this approach cannot be used with view attachments.
I've submitted FB22014370 about this issue.
Thank you.
RealityKit
RSS for tagSimulate and render 3D content for use in your augmented reality apps using RealityKit.
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I have a simple visionOS app that creates an Entity, writes it to the device, and then attempts to load it. However, when the entity file get overwritten, it affects the ability for the app to load it correctly.
Here is my code for saving the entity.
import SwiftUI
import RealityKit
import UniformTypeIdentifiers
struct ContentView: View {
var body: some View {
VStack {
ToggleImmersiveSpaceButton()
Button("Save Entity") {
Task {
// if let entity = await buildEntityHierarchy(from: urdfPath) {
let type = UTType.realityFile
let filename = "testing.\(type.preferredFilenameExtension ?? "bin")"
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
let fileURL = documentsURL.appendingPathComponent(filename)
do {
let mesh = MeshResource.generateBox(size: 1, cornerRadius: 0.05)
let material = SimpleMaterial(color: .blue, isMetallic: true)
let modelComponent = ModelComponent(mesh: mesh, materials: [material])
let entity = Entity()
entity.components.set(modelComponent)
print("Writing \(fileURL)")
try await entity.write(to: fileURL)
} catch {
print("Failed writing")
}
}
}
}
.padding()
}
}
Every time I press "Save Entity", I see a warning similar to:
Writing file:///var/mobile/Containers/Data/Application/1140E7D6-D365-48A4-8BED-17BEA34E3F1E/Documents/testing.reality
Failed to set dependencies on asset 1941054755064863441 because NetworkAssetManager does not have an asset entity for that id.
When I open the immersive space, I attempt to load the same file:
import SwiftUI
import RealityKit
import UniformTypeIdentifiers
struct ImmersiveView: View {
@Environment(AppModel.self) private var appModel
var body: some View {
RealityView { content in
guard
let type = UTType.realityFile.preferredFilenameExtension
else {
return
}
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
let fileURL = documentsURL.appendingPathComponent("testing.\(type)")
guard FileManager.default.fileExists(atPath: fileURL.path) else {
print("❌ File does not exist at path: \(fileURL.path)")
return
}
if let entity = try? await Entity(contentsOf: fileURL) {
content.add(entity)
}
}
}
}
I also get errors after I overwrite the entity (by pressing "Save Entity" after I have successfully loaded it once). The warnings that appear when the Immersive space attempts to load the new entity are:
Asset 13277375032756336327 Mesh (RealityFileAsset)URL/file:///var/mobile/Containers/Data/Application/1140E7D6-D365-48A4-8BED-17BEA34E3F1E/Documents/testing.reality/Mesh_0.compiledmesh failure: Asset provider load failed: type 'RealityFileAsset' -- RERealityArchive: Failed to open load stream for entry 'assets/Mesh_0.compiledmesh'.
Asset 8308977590385781534 Scene (RealityFileAsset)URL/file:///var/mobile/Containers/Data/Application/1140E7D6-D365-48A4-8BED-17BEA34E3F1E/Documents/testing.reality/Scene_0.compiledscene failure: Asset provider load failed: type 'RealityFileAsset' -- RERealityArchive: Failed to read archive entry.
AssetLoadRequest failed because asset failed to load '13277375032756336327 Mesh (RealityFileAsset)URL/file:///var/mobile/Containers/Data/Application/1140E7D6-D365-48A4-8BED-17BEA34E3F1E/Documents/testing.reality/Mesh_0.compiledmesh' (Asset provider load failed: type 'RealityFileAsset' -- RERealityArchive: Failed to open load stream for entry 'assets/Mesh_0.compiledmesh'.)
The order of operations to make this happen:
Launch app
Press "Save Entity" to save the entity
"Open Immersive Space" to view entity
Press "Save Entity" to overwrite the entity
"Open Immersive Space" to view entity, failed asset load request
Also
Launch app, the entity should still be save from last time the app ran
"Open Immersive Space" to view entity
Press "Save Entity" to overwrite the entity
"Open Immersive Space" to view entity, failed asset load request
NOTE: It appears I can get it to work slightly better by pressing the "Save Entity" button twice before attempting to view it again in the immersive space.
When using the new RealityKit Manipulation Component on Entities, indirect input will never translate the entity - no matter what settings are applied. Direct manipulation works as expected for both translation and rotation.
Is this intended behaviour? This is different from how indirect manipulation works on Model3D. How else can we get translation from this component?
visionOS 26 Beta 2
Build from macOS 26 Beta 2 and Xcode 26 Beta 2
Attached is replicable sample code, I have tried this in other projects with the same results.
var body: some View {
RealityView { content in
// Add the initial RealityKit content
if let immersiveContentEntity = try? await Entity(named: "MovieFilmReel", in: reelRCPBundle) {
ManipulationComponent.configureEntity(immersiveContentEntity, allowedInputTypes: .all, collisionShapes: [ShapeResource.generateBox(width: 0.2, height: 0.2, depth: 0.2)])
immersiveContentEntity.position.y = 1
immersiveContentEntity.position.z = -0.5
var mc = ManipulationComponent()
mc.releaseBehavior = .stay
immersiveContentEntity.components.set(mc)
content.add(immersiveContentEntity)
}
}
}
My application calculates three distinct Meesus Double [x, y, z] Radian values to light a sphere in RealityKit with DirectionalLight. It is my understanding that I must use (simd_quatf) for each radian value to properly light the sphere in the view. The code correctly [orientates] the sphere with the combined (simd_quatf) DirectionalLight in the view, but the illumination (Z-axis) fails to properly illuminate the sphere with the expected result, compared to associated Meesus web page images. For the moment, I do not know how to correct the (Z-axis). Curious for a suggestion ... :]
// Location values.
let theLatitude: Double = 51.13107260
let theLongitude: Double = -114.01127910
let currentDate: Date = Date()
struct TheCalculatedMoonPhaseTest_ContentView: View {
var body: some View {
VStack {
if #available(macOS 15.0, *) {
RealityView { content in
let moonSphere_Entity = Entity.createSphere(radius: 0.90, color: .black)
moonSphere.Entity.name = "MoonSphere"
moonSphere.Entity.position = SIMD3<Float>(x: 0, y: 0, z: 0)
content.add(moonSphere.Entity)
let sunLight_Entity = createDirectionalLight(latitude: theLatitude, longitude: theLongitude, date: currentDate)
content.add(sunLight_Entity)
} // End of [RealityView]
} else {
// Earlier version required.
} // End of [if #available(macOS 15.0, *)]
} // End of [VStack]
.background(Color.black)
} // End of [var body: some View]
// MARK: - 🟠🟠🟠🟠 [SET THE BACKGROUND COLOUR] 🟠🟠🟠🟠
var backgroundColor: Color = Color.init(.black)
// MARK: - 🟠🟠🟠🟠 [CREATE THE DIRECTIONAL LIGHT FOR THE SPHERE] 🟠🟠🟠🟠
func createDirectionalLight(latitude: Double, longitude: Double, date: Date) -> Entity {
let directionalLight = DirectionalLight()
directionalLight.light.color = .white
directionalLight.light.intensity = 1000000
directionalLight.shadow = DirectionalLightComponent.Shadow()
directionalLight.shadow?.maximumDistance = 5
directionalLight.shadow?.depthBias = 1
// MARK: 🟠🟠🟠🟠 Retrieve the [MEESUS MOON AGE VALUES] from the [CONSTANT FOLDER] 🟠🟠🟠🟠
let theMeesusMoonAge_LunarAgeDaysValue = 25.90567592898601
if theMeesusMoonAge_LunarAgeDaysValue >= 23.10 && theMeesusMoonAge_LunarAgeDaysValue < (29.530588853 - 1.00) {
let someCalculatedX_WestEastRadian: Float = Float(1.00)
// Identify the sphere’s DirectionalLight Tilt Angle (Y) radian value ::
// Note :: The following Tilt Angle is corrected to [Zenith] with the [MeesusCalculatedTilt_Angle] minus the [MeesusCalculatedPar_Angle].
let someCalculatedY_TiltAngleRadian: Float = Float(1.3396086)
// Identify the sphere’s DirectionalLight Illumination (Z) radian Value ::
// Note :: The Meesus calculated illumination fraction is converted to degrees, then converted to a radian value.
let someCalculatedZ_IlluminationAngleRadian: Float = Float(0.45176168630244457) // <=== 14.3800% Illumination.
// Define rotation angles in radians for X, Y, and Z axes.
let x_Radians = someCalculatedX_WestEastRadian
let y_Radians = someCalculatedY_TiltAngleRadian
let z_Radians = someCalculatedZ_IlluminationAngleRadian
// Identify and separate the quaternion [simd_quatf] for each Radian.
let q_X = simd_quatf(angle: x_Radians, axis: SIMD3<Float>(1, 0, 0))
let q_Y = simd_quatf(angle: y_Radians, axis: SIMD3<Float>(0, 1, 0))
let q_Z = simd_quatf(angle: z_Radians, axis: SIMD3<Float>(0, 0, 1))
// Apply and combine the rotations, where order matters.
let combinedRotation = q_Z * q_Y * q_X
// Identify the [Combined Rotation].
// The [MyMoonMeesus] :: [WANING CRESCENT] calculated [combinedRotation] :: simd_quatf(real: 0.73715997, imag: SIMD3<Float>(0.24427173, 0.61516714, -0.13599981)) ° Radians
// Normalize the [combinedRotation].
let theNormalizesRotation = simd_normalize(combinedRotation)
// Identify the [Normalized Combined Rotation].
// The [MyMoonMeesus] :: [WANING CRESCENT] calculated [normalizedRotation] :: simd_quatf(real: 0.73715997, imag: SIMD3<Float>(0.24427173, 0.61516714, -0.13599981)) ° Radians
// Assume the [theNormalizesRotation] appears reversed.
let theCorrectedRotation = theNormalizesRotation.inverse
// Identify the [Reversed Combined Rotation].
// The [MyMoonMeesus] :: [WANING CRESCENT] calculated [correctedRotation] :: simd_quatf(real: 0.73715997, imag: SIMD3<Float>(-0.24427173, -0.61516714, 0.13599981)) ° Radians
// Apply the [Corrected Rotation] to the entity.
directionalLight.transform.rotation *= theCorrectedRotation
// Add the [directionalLight] to the scene ::
let anchor = AnchorEntity()
anchor.addChild(directionalLight)
} // End of [if theMeesusMoonAge_LunarAgeDaysValue >= 23.10 && theMeesusMoonAge_LunarAgeDaysValue < (29.530588853 - 1.00)]
return directionalLight
} // End of [func createDirectionalLight(latitude: Double, longitude: Double, date: Date) -> Entity]
} // End of [struct TheCalculatedMoonPhaseTest_ContentView: View]
// MARK: 🟠🟠🟠🟠 [ENTITY HELPER EXTENSION] 🟠🟠🟠🟠
extension Entity {
static func createSphere(radius: Float, color: NSColor) -> Entity {
let mesh = MeshResource.generateSphere(radius: radius)
var material = PhysicallyBasedMaterial()
material.baseColor = .init(tint: color)
let modelComponent = ModelComponent(mesh: mesh, materials: [material])
let entity = Entity()
entity.components.set(modelComponent)
entity.components.set(Transform())
return entity
} // End of [static func createSphere(radius: Float, color: NSColor) -> Entity]
} // End of [extension Entity]
// Application Image :: Calgary
// Website Image :: timeanddate
// mooncalc.org
Hi, I'm trying to use AnchorEntity for horizontal surfaces.
It works when the entity is being created, but I'm looking for a way to snap this entity to the nearest surface, after translating it, for example with a DragGesture.
What would be the best way to achieve this? Using raycast, creating a new anchor, trackingMode to continuous etc.
Do I need to use ARKitSession as I want continuous tracking?
Hi, is there a way to track feet in a visionOS app in an immersive space? I want the whole body to be visible in VR, and I want to know if the user touches an object with their foot.
Hello, I'm struggling trying to interact with a RealityKit entity nested (or at least visually nested) in a second one.
I think I've the same issue as mentioned on this StackOverflow post, but I can't manage to reproduce the solution. https://stackoverflow.com/questions/79244424/how-to-prioritize-a-specific-entity-when-collision-boxes-overlap-in-realitykit
What I'd like to achieve is to translate the red box using a DragGesture, while still be able to interact using a TapGesture on the sphere. Currently, I can only do one at a time.
Does anyone know the solution?
extension CollisionGroup {
static let parent: CollisionGroup = CollisionGroup(rawValue: 1 << 0)
static let child: CollisionGroup = CollisionGroup(rawValue: 1 << 1)
}
struct ImmersiveView: View {
var body: some View {
RealityView { content in
let boxMesh = MeshResource.generateBox(size: 0.35)
let boxMaterial = SimpleMaterial(color: .red.withAlphaComponent(0.25), isMetallic: false)
let boxEntity = ModelEntity(mesh: boxMesh, materials: [boxMaterial])
let sphereMesh = MeshResource.generateSphere(radius: 0.05)
let sphereMaterial = SimpleMaterial(color: .blue, isMetallic: false)
let sphereEntity = ModelEntity(mesh: sphereMesh, materials: [sphereMaterial])
content.add(sphereEntity)
content.add(boxEntity)
boxEntity.components.set(InputTargetComponent())
boxEntity.components.set(
CollisionComponent(
shapes: [ShapeResource.generateBox(size: SIMD3<Float>(repeating: 0.35))],
isStatic: true,
filter: CollisionFilter(
group: .parent,
mask: .parent.subtracting(.child)
)
)
)
sphereEntity.components.set(InputTargetComponent())
sphereEntity.components.set(HoverEffectComponent())
sphereEntity.components.set(
CollisionComponent(
shapes: [ShapeResource.generateSphere(radius: 0.05)],
isStatic: true,
filter: CollisionFilter(
group: .child,
mask: .child.subtracting(.parent)
)
)
)
}
}
}
VideoMaterial Black Screen on Vision Pro Device (Works in Simulator)
App Overview
App Name: Extn Browser
Bundle ID: ai.extn.browser
Purpose: A visionOS web browser that plays 360°/180° VR videos in an immersive sphere environment
Development Environment & SDK Versions
Component
Version
Xcode
26.2
Swift
6.2
visionOS Deployment Target
26.2
Swift Concurrency
MainActor isolation enabled
App is released in the TestFlight.
Frameworks Used
SwiftUI - UI framework
RealityKit - 3D rendering, MeshResource, ModelEntity, VideoMaterial
AVFoundation - AVPlayer, AVAudioSession
WebKit - WKWebView for browser functionality
Network - NWListener for local proxy server
Sphere Video Mechanism
The app creates an immersive 360° video experience using the following approach:
// 1. Create sphere mesh (10 meter radius for immersive viewing)
let mesh = MeshResource.generateSphere(radius: 10.0)
// 2. Create initial transparent material
var material = UnlitMaterial()
material.color = .init(tint: .clear)
// 3. Create entity and invert sphere (negative X scale)
let sphere = ModelEntity(mesh: mesh, materials: [material])
sphere.scale = SIMD3<Float>(-1, 1, 1) // Inverts normals for inside-out viewing
sphere.position = SIMD3<Float>(0, 1.5, 0) // Eye level
// 4. Create AVPlayer with video URL
let player = AVPlayer(url: videoURL)
// 5. Configure audio session for visionOS
let audioSession = AVAudioSession.sharedInstance()
try audioSession.setCategory(.playback, mode: .moviePlayback, options: [.mixWithOthers])
try audioSession.setActive(true)
// 6. Create VideoMaterial and apply to sphere
let videoMaterial = VideoMaterial(avPlayer: player)
if var modelComponent = sphere.components[ModelComponent.self] {
modelComponent.materials = [videoMaterial]
sphere.components.set(modelComponent)
}
// 7. Start playback
player.play()
ImmersiveSpace Configuration
// browserApp.swift
ImmersiveSpace(id: appModel.immersiveSpaceID) {
ImmersiveView()
.environment(appModel)
}
.immersionStyle(selection: .constant(.mixed), in: .mixed)
Entitlements
<!-- browser.entitlements -->
<key>com.apple.security.app-sandbox</key>
<true/>
<key>com.apple.security.network.client</key>
<true/>
<key>com.apple.security.network.server</key>
<true/>
Info.plist Network Configuration
<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key>
<true/>
</dict>
The Issue
Behavior in Simulator: Video plays correctly on the inverted sphere surface - 360° video is visible and wraps around the user as expected.
Behavior on Physical Vision Pro: The sphere displays a black screen. No video content is visible, though the sphere entity itself is present.
Important: Not a DRM/Licensing Issue
This issue is NOT related to Digital Rights Management (DRM) or FairPlay. I have tested with:
Unlicensed raw MP4 video files (no DRM protection)
Self-hosted video content with no copy protection
Direct MP4 URLs from CDN without any licensing requirements
The same black screen behavior occurs with all unprotected video sources, ruling out DRM as the cause.
(Plain H.264 MP4, no DRM)
Screen Recording: Working in Simulator
The following screen recording demonstrates playing a 360° YouTube video in the immersive sphere on the visionOS Simulator:
https://cdn.commenda.kr/screen-001.mov
This confirms that the VideoMaterial and sphere rendering work correctly in the simulator, but the same setup shows a black screen on the physical Vision Pro device.
Observations
AVPlayer status reports .readyToPlay - The video appears to load successfully
VideoMaterial is created without errors - No exceptions thrown
Sphere entity renders - The geometry is visible (black surface)
Audio session is configured - No errors during audio session setup
Network requests succeed - The video URL is accessible from the device
Same result with local/unprotected content - DRM is not a factor
Console Logs (Device)
The logging shows:
Sphere created and added to scene
AVPlayer created with correct URL
VideoMaterial created and applied
Player status transitions to .readyToPlay
player.play() called successfully
Rate shows 1.0 (playing)
Despite all success indicators, the rendered output is black.
Questions for Apple
Are there known differences in VideoMaterial behavior between the visionOS Simulator and physical Vision Pro hardware?
Does VideoMaterial(avPlayer:) require specific video codec/format requirements that differ on device? (The test video is a standard H.264 MP4)
Is there a required Metal capability or GPU feature for VideoMaterial that may not be available in certain contexts on device?
Does the immersion style (.mixed) affect VideoMaterial rendering on hardware?
Are there additional entitlements required for video texture rendering in RealityKit on physical hardware?
Attempted Solutions
Configured AVAudioSession with .playback category
Added delay before player.play() to ensure material is applied
Verified sphere scale inversion (-1, 1, 1)
Tested multiple video URLs (including raw, unlicensed MP4 files)
Confirmed network connectivity on device
Ruled out DRM/FairPlay issues by testing unprotected content
Environment Details
Device: Apple Vision Pro
visionOS Version: 26.2
Xcode Version: 26.2
macOS Version: Darwin 25.2.0
Recently, applications for the Swift Student Challenge opened up. I noticed, that when selected "where to run your app" (mine was developed in Xcode 26), and you select Xcode26, there is a note underneath it that basically says all Xcode projects will be run on the simulator.
What if my project is dependent on AR? How would I let the judges test my submission?
Topic:
Community
SubTopic:
Swift Student Challenge
Tags:
Swift Student Challenge
ARKit
AR / VR
RealityKit
Hello,
I am experiencing an issue where lighting is disabled within a Portal Component specifically when using Progressive or Full Immersion styles in visionOS 26.2.
[Steps to Reproduce]
Create a scene in Reality Composer Pro with custom lighting (Directional Light, IBL, etc.) and load it as an Entity.
Add a PortalComponent to this Entity.
Observe the Entity in an ImmersiveSpace under different Immersion Styles.
[Observed Behavior]
Mixed Immersion: Lighting works as expected.Progressive / Full Immersion: Lighting is disabled, causing the content to render incorrectly.
[Additional Context]
Without PortalComponent: The same Reality Composer Pro scene renders lighting correctly across all Immersion Styles (Mixed, Progressive, and Full).Regression: In applications built with Xcode 16.4 / visionOS 2.5, lighting inside the Portal functioned correctly. This issue appears to have emerged with Xcode 26.2 and visionOS 26.2.
[Questions]
Is the disabling of lighting inside Portals during Full/Progressive Immersion an intended architectural change or optimization in visionOS 26.2?
Are there any workarounds, such as specific PortalComponent configurations or new API flags, to re-enable lighting in these immersion modes?
Thank you.
Topic:
Spatial Computing
SubTopic:
Reality Composer Pro
Tags:
AR / VR
RealityKit
Reality Composer Pro
My procedural animation using IKRig occasionally jitters and throws this warning. It completely breaks immersion.
getMoCapTask: Rig must be of type kCoreIKSolverTypePoseRetarget
Any idea where to start looking or what could be causing this?
Hi everyone,
I’m working with RealityKit on visionOS and I’m seeing unexpected behavior when the user long-presses the Digital Crown, which recenters the world.
Observed behavior:
When the world is recentered via long-pressing the Crown, the models remain visually in the correct place (as expected).
However, if I query the model’s position or transform immediately after recentering (e.g. entity.position or similar), I still get the old values from before recenter.
As soon as I interact with the model using a gesture (drag/rotate/scale), the position updates and then querying it returns the correct, updated values.
So effectively:
Recenter happens
Visual position is correct
Programmatic position remains stale
First gesture causes the position to “snap” to the correct updated value
Questions:
Is there any event, notification, or callback that fires when the world is recentered due to a long press of the Crown button?
Is there a recommended way to get the updated world-space transform immediately after recenter, without waiting for a gesture?
Is this expected behavior due to deferred/lazy transform updates in RealityKit?
Right now it feels like recentering updates the coordinate system but doesn’t immediately commit new transform values to entities until some interaction occurs.
Any guidance or best-practice patterns for handling this would be appreciated.
Thanks!
Hi everyone,
I'm new to visionOS development. I'm trying to create a physics-based scene (with gravity) where users can pick up and move objects on a workbench. I am struggling with physics interactions during the drag gesture:
Kinematic Mode: If I switch to .kinematic during the drag, the object moves smoothly but clips through other objects (no collisions).
Dynamic Mode: I tried keeping it .dynamic and applying linear velocity toward the hand position, but the movement feels laggy and unresponsive.
Hybrid Approach: I tried switching to .kinematic during DragGesture.onChange and back to .dynamic on collision, but this causes the entity to jitter/shake violently when touching other objects.
Has anyone found a clean way to drag objects while maintaining solid collisions.
Thanks for your help!
Hi. I'm trying to show 3D or AR content in multiple pages on an iOS app but I have found that if a RealityView is used earlier in a flow then future uses will never display the camera feed, even if those earlier uses do not use any spatial tracking.
For example, in the following simplified view, the second page realityView will not display the camera feed even though the first view does not use it not start a tracking session.
struct ContentView: View {
var body: some View {
NavigationStack {
VStack {
RealityView { content in
content.camera = .virtual
// showing model skipped for brevity
}
NavigationLink("Second Page") {
RealityView { content in
content.camera = .spatialTracking
}
}
}
}
}
}
What is the way around this so that 3D content can be displayed in multiple places in the app without preventing AR content from working?
I have also found the same problem when wrapping an ARView for use in SwiftUI.
I have written this function:
@available(macOS 26.0, *)
func instancing() async -> Entity {
let entity = Entity()
do {
// 1. Create a CustomMaterial
let library = offscreenRenderer.pointRenderer!.device.makeDefaultLibrary()!
let surfaceShader = CustomMaterial.SurfaceShader(
named: "surfaceShaderWithCustomUniforms", // This must match the function name in Metal
in: library
)
let instanceCount = 10
// No idea how to actually use this...
// let bufferSize = instanceCount * MemoryLayout<UInt32>.stride
//
// // Create the descriptor
// var descriptor = LowLevelBuffer.Descriptor(capacity: bufferSize, sizeMultiple: MemoryLayout<UInt32>.stride)
//
// // Initialize the buffer
// let lowLevelBuffer = try LowLevelBuffer(descriptor: descriptor)
// lowLevelBuffer.withUnsafeMutableBytes { rawBytes in
// // Bind the raw memory to the UInt32 type
// let pointer = rawBytes.bindMemory(to: UInt32.self)
// pointer[1] = 0xff_0000
// pointer[0] = 0x00_ff00
// pointer[2] = 0x00_00ff
// pointer[3] = 0xff_ff00
// pointer[4] = 0xff_00ff
// pointer[5] = 0x00_ffff
// pointer[6] = 0xff_ffff
// pointer[7] = 0x7f_0000
// pointer[8] = 0x00_7f00
// pointer[9] = 0x00_007f
// }
var material = try CustomMaterial(surfaceShader: surfaceShader, lightingModel: .lit)
material.withMutableUniforms(ofType: SurfaceCustomUniforms.self, stage: .surfaceShader) { params, resources in
params.argb = 0xff_0000
}
// 2. Create the ModelComponent (provides the MESH and MATERIAL)
let mesh = MeshResource.generateSphere(radius: 0.5)
let modelComponent = ModelComponent(mesh: mesh, materials: [material])
// 3. Create the MeshInstancesComponent (provides the INSTANCE TRANSFORMS)
let instanceData = try LowLevelInstanceData(instanceCount: instanceCount)
instanceData.withMutableTransforms { transforms in
for i in 0..<instanceCount {
let instanceAngle = 2 * .pi * Float(i) / Float(instanceCount)
let radialTranslation: SIMD3<Float> = [-sin(instanceAngle), cos(instanceAngle), 0] * 4
// Position each sphere around a circle.
let transform = Transform(
scale: .one,
rotation: simd_quatf(angle: instanceAngle, axis: [0, 0, 1]),
translation: radialTranslation
)
transforms[i] = transform.matrix
}
}
let instancesComponent = try MeshInstancesComponent(mesh: mesh, instances: instanceData)
// 4. Attach BOTH to the same entity
entity.components.set(modelComponent)
entity.components.set(instancesComponent)
} catch {
print("Failed to create mesh instances: \(error)")
}
return entity
}
and this is the corresponding Metal shader
typedef struct {
uint32_t argb;
} SurfaceCustomUniforms;
[[stitchable]]
void surfaceShaderWithCustomUniforms(realitykit::surface_parameters params,
constant SurfaceCustomUniforms &customParams)
{
half3 color = {
static_cast<half>((customParams.argb >> 16) & 0xff),
static_cast<half>((customParams.argb >> 8) & 0xff),
static_cast<half>(customParams.argb & 0xff) };
params.surface().set_base_color(color);
}
which works well and generates 10 red spheres. While listening to the WWDC25 presentation on what's new in RealityKit I am positive to hear the presenter saying that it is possible to customise each instance using a LowLevelBuffer, but so far all my attempts have failed.
Is it possible, and if so how ?
Thanks for reading and for your help.
Kind regards,
Christian
So with the new ManipulationComponent, we can choose "stay" and then if you drag it out of your volume, once you let go it will instantly disappear.
We can "animate" it back to inside the volume, eg.:
content.subscribe(to: ManipulationEvents.WillRelease.self) { event in
Entity.animate(
.easeInOut(duration: 1),
body: { event.entity.position = [0, 0.2, 0] },
completion: {}
)
},
Howeve,r for the duration that it travels outside of the volume it's invisible the whole time.
In this apple video, it seems to be visible when dragging and when letting go, but perhaps that's not a volume they're dragging it out of?
https://youtu.be/VtenPKrvPOU?si=y1zoZOs2IMyDzOm6&t=1748
Does anyone know how to keep the entity visible even when after letting the entity go while you animate it back towards inside of your volume?
I am using AccessoryTrackingProvider from ARKit to get the transform of the PSVR2 controller via originFromAnchorTransform of the AccessoryAnchor. I also am trying to use AnchorEntity on the controller using RealityKit
However, none of the three options for Accessory.LocationName, which should be used to define the AnchorEntity target, seem to match the position on the controller which is being sent from ARKit.
The picture attached is showing two transforms:
RealityKit - using .gripSurface to define the AnchoringComponent.Target.accesssory location.
ARKit - using originFromAnchorTransform for AccessoryTrackingProvider.
They are not aligned at the same point.
As for the other options of Accessory.LocationName, using .aim is located at the tip of the controller and .grip is the same position as .gripSurface but with a different orientation.
I am wondering why there is not an option for Accessory.LocationName that actually matches the transform captured by ARKit?
This post documents an issue I reported in feedback FB19610114 and see if anyone knows of a workaround. Here is a copy of the feedback.
Short version
Manipulation (SwiftUI OR RealityKit) fails to translate entities after changing rooms. By changing rooms, I mean a human wearing an Apple Vision Pro leaving one room and entering another room. Once this issue occurs, it impacts all apps that use these features. A device restart is the only solution I have to fix it.
Feedback FB19610114
This is an odd one. I'm using the new Manipulation Component in visionOS 26. Most of the time this works well. Sometime it stops working and when it does the only way to get it working again is to reboot the headset.
When this happens, I can continue to rotate and scale items, but translation no longer works. It is as if the item is stuck to a fixed point in the parent scene (window, volume, etc). When this bug occurs, it affects every app across the entire operating system that is using manipulation, including the RealityKit component AND the SwiftUI version. This is not limited to one app and is not limited to apps that I am working on. Once this error occurs, it affects literally any application across the operating system that is using this API, including apps from Apple.
I won't speculate on the cause of this, but I do know of one way where I can always get it to happen.
Here is how to reproduce it:
Make an Xcode project with a single entity that uses the Manipulation Component. There is no need to customize the configuration of this component. The default implementation will work.
Build and run this app on device. You can keep running from device or quit and launch the app like normal on device.
Open the app and manipulate the entity - it should work as expected.
Physically walk into another room. It is vital that you leave the current room that you are in and enter a different room entirely.
Use the digital crown to recenter your view and bring your window or volume to you.
Test the manipulation on the entity again - it should still be working as expected at this point.
Physically, move yourself and your headset into the original room where you started.
Use the digital crown to recenter your view and bring your window or volume to you.
Test the manipulation on the entity again - you should now see the issue.
When I follow the steps above, then 100% of the time manipulation translation stops working at this point. It will impact any application using this API. The only way to fix it is to restart my headset.
A few points to keep in mind
It does not matter if an app is actively being run from Xcode.
When this occurs, it impacts every single app, not just one.
When this occurs, rotation and scaling continue to work, but the entity/view cannot be translated.
This impacts BOTH the SwiftUI version and the RealityKit version.
When this occurs, the only way to "fix" it is to reboot the device.
I have a ModelEntity with GroundingShadowComponent
entity.enumerateHierarchy { child, stop in
child.components.set(GroundingShadowComponent(castsShadow: true))
}
When I set it on the table, I can see the shadow on the table, even if I disable plane detection. However, when I enable plane detection, and the plane's material is OcclusionMaterial. I can not see the shadow on the table. As far as I know, receivesDynamicLighting is not usable in VisionOS. So how can I cast shadow on OcclusionMaterial in VisionOS? Or rather, is it possible to have the shadow properly displayed on the tabletop while ensuring that I cannot see objects beneath the table through it?
Apple's new Spatial Personas use Gaussian Splatting,
but I have not found any APIs for visionOS to display a Gaussian Splat like a PLY file.
Am I just missing the Apple documentation? If not, are there common practices developers are using for displaying Gaussian Splats in visionOS?