Using Reality Composer Pro 2.0, I created a simple shader graph that displays a texture on an unlit surface:
On visionOS 2 beta, I can successfully use ShaderGraphMaterial(named:from:in:) to load that shader graph material and assign it to a model entity.
However, on visionOS 1.2 and earlier, either in Simulator or on the device, ShaderGraphMaterial(named:from:in:) fails and I see the following logged to the console:
If, using Reality Composer Pro 1.0, I experimentally open the same project and delete and recreate exactly the same nodes above, then ShaderGraphMaterial(named:from:in:) works as expected on visionOS 1.2.
Is it a known issue that Reality Composer 2 can't be used with visionOS 1?
Is this intentional behavior?
I've submitted feedback as FB14828873, including a sample project and repro steps.
If possible, I would appreciate guidance from an Apple engineer, like "This is a known issue for [list of node types]" or "Reality Composer Pro 2 is not supported for visionOS 1 development, please refer to [documentation]" or "We recommend [workaround]."
Thank you.
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In my app, I have an ARView that has cameraMode set to nonAR.
I occasionally hide the ARView when it is not needed and reveal it again later.
While the ARView is hidden, I'd like to pause the animation to save iPhone battery life. I'd also like to do this when I know that animation in my scene has paused and the contents of the view, although still visible, is static.
This was possible using SceneKit, but I can't seem to find an equivalent way to do it using RealityKit.
At least as of iOS 18, a hidden ARView with an empty scene appears to use approximately 30% of the CPU.
How can I pause ARView so that it won't use the battery unnecessarily?
Thank you for considering this question.
My experience has been that ModelEntity(named:in:) can be used to load a USD file with a simple structure consisting of entities and model entities, and, critically, it will flatten the entity hierarchy down to a single ModelEntity, presumably reducing the number of draw calls.
However, can anyone verify that the following is true?
If ModelEntity(named:in:) is used to load a USD file from a RealityKit content bundle, it may fail when the USD file contains more complex data, such as shader graph material definitions, or perhaps for some other reason. I am not sure.
AND the error that ModelEntity(named:in:) throws in this case is
Cannot load RealityKitContent entity: Failed to find resource with name "<name>" in bundle
which would literally suggest that the file does not exist, instead of what I assume the error actually is, which is "the file exists but its entity hierarchy could not be flattened to a single ModelEntity" ?
Is that an accurate description of the known behavior of ModelEntity:named:in:)?
I understand that I could use Entity(named:in:) instead, without the flattening feature. My question is really more about the seemingly misleading error message.
Thank you for any clarification you can provide.
In Reality Composer Pro 2.0 (448.120.2), if I use the "Create new scene in the project" button more than once, this feature doesn't seem to work.
The second time I use "Create new scene in the project", Reality Composer Pro displays a new empty USDA file in the project browser with the wrong icon (a yellow document icon instead of a 3D box icon).
Also, it doesn't create the new scene's USDA file on disk or display the scene in entity hierarchy browser or create a new tab.
Consequently, whenever I want to add more than one new scene to my project, I have to repeatedly quit and restart Reality Composer Pro.
In my use of RCP just now, I had to quit and restart RCP six times to create seven new scenes.
Is this a known issue?
Repro steps:
In a Reality Composer Pro project, create a new folder using the "add folder" icon button in the project browser.
Inside the new folder, click the "Create new scene in the project" icon button.
Click the "Create new scene in the project" icon button a second time.
Expected behavior:
A new USDA file is created on disk. The new USDA file's root entity appears in the entity hierarchy browser and a corresponding new tab is created.
Observed behavior:
The USDA file for this scene is not created on disk and it does not appear in the entity hierarchy browser in a new tab. In the project browser view, a yellow document icon appears and it does not appear to correspond to an actual USDA file.
Thank you for any insight you can provide about this issue.
I'm watching the session video "What's new in Xcode 26" and when I try out the new #Playground macro (in the context of a local package in my project) I see only this activity indicator for about 10-15 minutes:
Eventually I do see this error:
Despite the error, my local package does not import SwiftUI and has no dependencies other than Foundation.
I checked the Xcode 26 release notes and I don't see this issue mentioned.
A clean build of my project takes 55 seconds. Is it expected behavior that #Playground would require 10+ minutes to spin up?
Is there anything I can to do make the new #Playground macro work correctly?
Thank you.
On iPadOS 26 beta, the navigation bar can appear inset underneath the status bar (FB18241928)
This bug does not happen on iOS 18.
This bug occurs when a full screen modal view controller without a status bar is presented, the device orientation changes, and then the full screen modal view controller is dismissed.
This bug appears to happen only on iPad, and not on iPhone.
This bug happens both in the simulator and on the device.
Thank you for investigating this issue.
I've loaded a ShaderGraphMaterial from a RealityKit content bundle and I'm attempting to access the initial values of its parameters using getParameter(handle:), but this method appears to always return nil:
let shaderGraphMaterial = try await ShaderGraphMaterial(named: "MyMaterial", from: "MyFile")
let namedParameterValue = shaderGraphMaterial.getParameter(name: "myParameter")
// This prints the value of the `myParameter` parameter, as expected.
print("namedParameterValue = \(namedParameterValue)")
let handle = ShaderGraphMaterial.parameterHandle(name: "myParameter")
let handleParameterValue = shaderGraphMaterial.getParameter(handle: handle)
// Expected behavior: prints the value of the `myParameter` parameter, as above.
// Observed behavior: prints `nil`.
print("handleParameterValue = \(handleParameterValue)")
Is this expected behavior?
Based on the documentation at https://developer.apple.com/documentation/realitykit/shadergraphmaterial/getparameter(handle:) I'd expect getParameter(handle:) to return the value of the parameter, just as getParameter(name:) does.
I've tested this on iOS 18.5 and iOS 26.0 beta 2.
Assuming this getParameter(handle:) works as designed, is the following ShaderGraphMaterial extension an appropriate workaround, or can you recommend a better approach?
Thank you.
public extension ShaderGraphMaterial {
/// Reassigns the values of all named material parameters using the handle-based API.
///
/// This works around an issue where, at least as of RealityKit 26.0 beta 2 and
/// earlier, `getParameter(handle:)` will always return `nil` when used to read the
/// initial value of a shader graph material parameter read using
/// `ShaderGraphMaterial(named:from:in:)`, whereas `getParameter(name:)` will work
/// as expected.
private mutating func copyNamedParametersToHandles() {
for parameterName in self.parameterNames {
if let value = self.getParameter(name: parameterName) {
let handle = ShaderGraphMaterial.parameterHandle(name: parameterName)
do {
try self.setParameter(handle: handle, value: value)
} catch {
assertionFailure("Cannot set parameter value")
}
}
}
}
}
Topic:
Graphics & Games
SubTopic:
RealityKit
Tags:
RealityKit
Reality Composer Pro
Shader Graph Editor
visionOS
TL;DR: RealityKit and Reality Composer Pro aren't forward or backward compatible with each other, and the resulting error message is terse and unhelpful. (FB14828873)
So far, I've been sticking with Xcode 16.4 for development and only using Xcode 26.0 beta experimentally.
Yesterday, I used xcode-select to switch to Xcode 26.0 beta 3 to test it, but I forgot to switch back.
Consequently, this morning I unintentionally used the future Reality Composer Pro (the version included with Xcode 26) to make a small change to a USD file.
Now I realize that if I'm unlucky, it's possible Reality Composer Pro may have silently introduced a small change into the USD file that may make RealityKit fail to read the file on iOS 18 and visionOS 2, which in the past has resulted in hours of debugging to track down the source of the failure, often a single line in the USD file that RealityKit can't communicate to me other than with the error "the operation couldn't be completed".
As an analogy, this situation is as if, during regular development (not involving Reality Composer Pro), Xcode didn't warn you about specific API version conflicts, but instead failed with a generic error message, without highlighting the line in your Swift file that was the source of the error.
During regular use, RealityKit generates an excessive amount of internal logging that is not actionable by third party developers. When developing an iOS RealityKit/ARKit app, this makes the Xcode console challenging to use for regular work.
(FB19173812)
See screenshots below.
Xcode does have an option for filtering out logging from specific SDKs, but enabling this feature to suppress the logging of RealityKit and related SDKs like PHASE is something developers have to do dozens of times each day. After a year of developing a RealityKit app, this process becomes frustrating.
If SDKs like Foundation, UIKit, and SwiftUI generated as much logging as RealityKit and related SDKs, Xcode's console would be unusable.
Is there any way to disable the logging of RealityKit and PHASE permanently?
Thank you for any help you provide.
Will visionOS support SceneKit?
I am creating an AR app that uses ARKit and SceneKit.
Will visionOS support SceneKit AR applications, or will I have to rewrite my app using RealityKit?
Thanks for answering my question.
: - )
Hey everybody!
Does anyone know if there's a UIKit API that's equivalent to SwiftUI's View/offset(z:)?
https://developer.apple.com/documentation/swiftui/view/offset(z:)
I'd like to translate a UIView forward in space a little bit on visionOS.
❤️
In RealityKit in visionOS 1.0 I'm perplexed that PhysicallyBasedMaterial and CustomMaterial have faceCulling properties but ShaderGraphMaterial does not.
Is there some way to achieve front face culling in a shader graph without creating a separate mesh with reversed triangle vertex indices?
Topic:
Graphics & Games
SubTopic:
RealityKit
Tags:
RealityKit
visionOS
Reality Composer Pro
Shader Graph Editor
I've created a minimal iOS RealityKit/ARKit app with only this view controller:
import UIKit
import RealityKit
import ARKit
class ViewController: UIViewController {
var arView: ARView!
override func viewDidLoad() {
super.viewDidLoad()
arView = ARView(frame: view.bounds, cameraMode: .nonAR, automaticallyConfigureSession: true)
arView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(arView)
}
}
When I run this app in the iOS 18.1 simulator using Xcode 16.1 beta 2 (16B5014f), RealityKit logs the warnings included below to the console.
I see similar warnings on the device, running iOS 18.0.
Should I be concerned about any of these warnings?
Please let me know if I should submit feedback reporting this issue.
Thank you.
Could not locate file 'default-binaryarchive.metallib' in bundle. Registering library (/Library/Developer/CoreSimulator/Volumes/iOS_22B5045f/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.1.simruntime/Contents/Resources/RuntimeRoot/System/Library/PrivateFrameworks/CoreRE.framework/default.metallib) that already exists in shader manager. Library will be overwritten. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/suFeatheringCreateMergedOcclusionMask.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arKitPassthrough.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arSegmentationComposite.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute0.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute1.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute2.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute3.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute4.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute5.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute6.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute7.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute8.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute9.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute10.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute11.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. Could not resolve material name 'engine:BuiltinRenderGraphResources/AR/arInPlacePostProcessCombinedPermute12.rematerial' in bundle at '/Users/drew/Library/Developer/CoreSimulator/Devices/6BCC578D-5046-49E6-B149-390576C7241D/data/Containers/Bundle/Application/75E15C63-F1D2-487F-A057-EBA2D45582C3/ARViewFailApp.app'. Loading via asset path. ... Compiler failed to build request makeRenderPipelineState failed [reading from a rendertarget is not supported]. Pipeline for technique meshShadowCasterProgrammableBlending failed compilation!
For a UIKit app based on scenes (UIScene), is it safe to reference UserDefaults in code that is executed from UIApplicationDelegate/application(_: didFinishLaunchingWithOptions:) ?
I've read that in iOS 15, there were undocumented scenarios involving app prewarming that would cause UserDefaults reads to fail within a window of time after device reboots, as described at https://christianselig.com/2024/10/beware-userdefaults/
The failure mode is that an app would be released, and months later, a small fraction of users would report failures consistent with UserDefaults reads unexpectedly returning nil, causing a loss of data. The user experience is bad, and debugging this behavior is then challenging because of how rarely it occurs.
Apple's https://developer.apple.com/documentation/uikit/app_and_environment/responding_to_the_launch_of_your_app/about_the_app_launch_sequence#3894431 seems to suggest that prewarming only executes an app "up until, but not including when main() calls UIApplicationMain(_:_:_:_:), but https://stackoverflow.com/questions/71025205/ios-15-prewarming-causing-appwilllaunch-method-when-prewarm-is-done documents that UIApplicationDelegate/application(_: didFinishLaunchingWithOptions:) has in fact been observed executing during app prewarming in scene-based apps.
So, my question: In an app based on scenes, if I'd like to reference UserDefaults within UIApplicationDelegate/application(_: didFinishLaunchingWithOptions:), when is it safe to do this?
I'm guessing the answer is one of these:
Never.
Only in apps that don't support scenes.
Only in iOS 16 or later.
Only in IOS 17 or later.
Is it guaranteed safe to reference UserDefaults in UIWindowSceneDelegate/scene(_:willConnectTo:options:) or later?
Is there documentation from Apple regarding this issue?
Thank you.