Generate Sphere in AR.

TODO: collapasable, copyable, download, etc

I'm building a VisionOs app, so realitykit and arkit... I want to generateSphere and place it 1 meter in front of me in the room. We are already in an immersive realitykit view, I just want to write a function that returns an Entity, all ready to be added to contentUser is building a VisionOS app using RealityKit and ARKit.Model set context updated.To generate a sphere and place it 1 meter in front of you in an immersive RealityKit view, you can create a function that returns an Entity with the sphere and its appropriate transform. Here is how you can achieve this:

import RealityKit
import ARKit

func generateSphere() -> Entity {
    // Create a mesh resource for a sphere
    let sphereMesh = MeshResource.generateSphere(radius: 0.1) // Adjust the radius as needed

    // Create a material for the sphere
    let material = SimpleMaterial(color: .blue, isMetallic: false)

    // Create a model entity with the mesh and material
    let sphereEntity = ModelEntity(mesh: sphereMesh, materials: [material])

    // Set the position of the sphere 1 meter in front of the user
    sphereEntity.position = SIMD3(x: 0, y: 0, z: -1)

    return sphereEntity
}

To use this function, you can add the returned Entity to your RealityKit scene content:

func addSphereToScene(scene: RealityKit.Scene) {
    let sphereEntity = generateSphere()
    scene.addAnchor(AnchorEntity(world: sphereEntity.position))
    scene.anchors.first?.addChild(sphereEntity)
}

Make sure you have your RealityKit and ARKit setup correctly in your VisionOS app. This function generateSphere() will create a sphere with a blue color, place it 1 meter in front of the user, and return it ready to be added to your content. Adjust the parameters as needed for your specific application.Okay, I have ``` content.subscribe(to: CollisionEvents.Began.self) { event in print("We have a collision folks entityA= (event.entityA.name)") print("We have a collision folks entityB= (event.entityB.name)") // TODO: play particles // TODO: play explosion

            content.remove(event.entityA)
        }

But I get the error `Escaping closure captures 'inout' parameter 'content'`

How can I fix this?The error `Escaping closure captures 'inout' parameter 'content'` occurs because the closure passed to the `subscribe` method captures the `content` parameter, which is marked as `inout`. Inout parameters cannot be captured by escaping closures because it would allow them to be accessed after the function they belong to has finished executing.

To fix this, you can use a weak reference to `content` within the closure to avoid capturing it directly. Here’s how you can do it:

1. Make `content` an instance variable of the class if it isn't already.
2. Use `[weak self]` in the closure to avoid retaining `self` strongly.

Here is an example:

```swift
import RealityKit

class YourViewController: UIViewController {
    var content: RealityKit.Scene!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Your setup code for content here
        
        subscribeToCollisionEvents()
    }
    
    func subscribeToCollisionEvents() {
        content.subscribe(to: CollisionEvents.Began.self) { [weak self] event in
            guard let self = self else { return }
            print("We have a collision folks entityA= \(event.entityA.name)")
            print("We have a collision folks entityB= \(event.entityB.name)")
            // TODO: play particles
            // TODO: play explosion
            
            self.content.remove(event.entityA)
        }
    }
}

In this example:

• content is an instance variable of YourViewController.
• subscribeToCollisionEvents sets up the collision event subscription.
• [weak self] is used to ensure that the closure does not retain self strongly, preventing potential retain cycles.
• guard let self = self else { return } ensures that self is available within the closure before using it.

This way, the closure captures a weak reference to self, and you avoid the inout parameter issue.It says weak doesn't apply to types. Here is my full code ``` import SwiftUI import RealityKit import RealityKitContent

struct StackingView: View { @StateObject var model = HandTrackingViewMOdel() var enemy = Enemy()

var body: some View {
    RealityView {
        content in
        content.add(model.setupContentEntity())
        
        content.add(enemy.createEnemy())
        let foo = content.subscribe(to: CollisionEvents.Began.self) { [weak self] event in
            print("We have a collision folks entityA= \(event.entityA.name)")
            print("We have a collision folks entityB= \(event.entityB.name)")
            // TODO: play particles
            // TODO: play explosion
            
            content.remove(event.entityA)
        }
        // TODO: foo.cancel()
    }.task {
        // run ARKitSession
        await model.runSession()
    }.task {
        // process hand updates
        await model.processHandUpdates()
    }.task {
        // process our world reconstruction
        await model.processReconstructionUpdates()
        
    }.task {
        await model.processPlaneDetectionUpdates()
    }.task {
        print("TODO")
    }.gesture(SpatialTapGesture().targetedToAnyEntity().onEnded({
        value in
        Task {
            print("Spatial Tap gesture occurred")
            // Place our cube
            await model.placeCube()
        }
        
    }))
    Text(/*@START_MENU_TOKEN@*/"Hello, World!"/*@END_MENU_TOKEN@*/)
}

}

#Preview { StackingView() } ```Given that RealityView is a SwiftUI view and you are encountering issues with capturing content inside an escaping closure, you can use an alternative approach to avoid capturing inout parameters directly. Specifically, you should use a separate method to handle the subscription and pass in the necessary references.

Here is how you can refactor your code:

1. Create a separate function to handle the collision event subscription.
2. Ensure that content is passed correctly and is not captured directly in the closure.

Here's the updated code:

import SwiftUI
import RealityKit
import RealityKitContent

struct StackingView: View {
    @StateObject var model = HandTrackingViewModel()
    var enemy = Enemy()

    var body: some View {
        RealityView { content in
            content.add(model.setupContentEntity())
            content.add(enemy.createEnemy())
            subscribeToCollisions(content: content)
        }
        .task {
            // Run ARKitSession
            await model.runSession()
        }
        .task {
            // Process hand updates
            await model.processHandUpdates()
        }
        .task {
            // Process our world reconstruction
            await model.processReconstructionUpdates()
        }
        .task {
            await model.processPlaneDetectionUpdates()
        }
        .task {
            print("TODO")
        }
        .gesture(SpatialTapGesture().targetedToAnyEntity().onEnded { value in
            Task {
                print("Spatial Tap gesture occurred")
                // Place our cube
                await model.placeCube()
            }
        })
        Text(/*@START_MENU_TOKEN@*/"Hello, World!"/*@END_MENU_TOKEN@*/)
    }

    func subscribeToCollisions(content: RealityKit.Scene) {
        content.subscribe(to: CollisionEvents.Began.self) { event in
            print("We have a collision folks entityA= \(event.entityA.name)")
            print("We have a collision folks entityB= \(event.entityB.name)")
            // TODO: play particles
            // TODO: play explosion

            content.remove(event.entityA)
        }
    }
}

#Preview {
    StackingView()
}

In this version:

• subscribeToCollisions is a separate method that takes content as a parameter. This avoids capturing content as an inout parameter in an escaping closure.
• The RealityView still sets up the scene and adds entities as before.
• The content.subscribe call is moved to the subscribeToCollisions method, which allows it to be properly encapsulated without capturing the inout parameter.

This should resolve the error and correctly handle collision events in your VisionOS app.

Generate Sphere in AR. created at Tue Jan 20 1970 20:58:30 GMT+0000 (Coordinated Universal Time)