如何在RealityKit游戏中同时实现2D HUD与3D内容的交互？

1. 自定义SpriteView的UIViewRepresentable #

直接用SwiftUI原生SpriteView无法灵活控制事件传递，需要自定义UIViewRepresentable包装SKView，同时持有RealityView的引用：

import SwiftUI
import SpriteKit
import RealityKit

struct SpriteKitHUDView: UIViewRepresentable {
    @Binding var scene: SKScene
    weak var realityView: ARView?
    
    func makeUIView(context: Context) -> SKView {
        let skView = SKView()
        skView.isUserInteractionEnabled = true
        skView.allowsTransparency = true
        skView.scene = scene
        return skView
    }
    
    func updateUIView(_ uiView: SKView, context: Context) {
        if uiView.scene !== scene {
            uiView.scene = scene
        }
    }
}

2. 在SpriteKit Scene中控制事件转发 #

在你的SKScene子类里，重写触摸方法，只处理HUD按钮的交互，非按钮区域的事件直接转发给RealityView：

class HUDScene: SKScene {
    weak var realityView: ARView?
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let touch = touches.first else { return }
        let touchLoc = touch.location(in: self)
        
        // 检查是否点击到HUD按钮
        if let button = atPoint(touchLoc) as? SKButtonNode { // 替换成你的按钮节点类型
            button.triggerAction()
            return
        }
        
        // 非按钮区域，转发事件给RealityView
        realityView?.touchesBegan(touches, with: event)
    }
    
    // 按需重写其他触摸方法，保持事件同步
    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        realityView?.touchesMoved(touches, with: event)
    }
    
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        realityView?.touchesEnded(touches, with: event)
    }
}

3. 在ContentView中关联视图 #

通过onAppear获取RealityView的引用，传递给HUDScene：

struct ContentView: View {
    @State private var hudScene = HUDScene(size: UIScreen.main.bounds.size)
    @State private var arView: ARView?
    
    var body: some View {
        ZStack {
            RealityView { content in
                // 添加你的3D内容
                let box = ModelEntity(mesh: .generateBox(size: 0.5))
                content.add(box)
            }
            .onAppear {
                // 获取底层ARView实例
                arView = UIApplication.shared.windows.first?.rootViewController?.view.subviews.first(where: { $0 is ARView }) as? ARView
                hudScene.realityView = arView
            }
            
            SpriteKitHUDView(scene: $hudScene, realityView: arView)
                .ignoresSafeArea()
        }
    }
}

如果完全不想依赖SwiftUI，直接基于UIKit构建ViewController，事件控制更直接：

import UIKit
import RealityKit
import SpriteKit

class GameViewController: UIViewController {
    private var arView: ARView!
    private var skView: SKView!
    private var hudScene: HUDScene!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 初始化RealityView
        arView = ARView(frame: view.bounds)
        view.addSubview(arView)
        
        // 添加3D内容
        let box = ModelEntity(mesh: .generateBox(size: 0.5))
        let anchor = AnchorEntity(world: .zero)
        anchor.addChild(box)
        arView.scene.addAnchor(anchor)
        
        // 初始化SpriteKit HUD
        hudScene = HUDScene(size: view.bounds.size)
        hudScene.realityView = arView
        
        skView = SKView(frame: view.bounds)
        skView.isUserInteractionEnabled = true
        skView.allowsTransparency = true
        skView.scene = hudScene
        view.addSubview(skView)
    }
}

• 开启SKView的allowsTransparency = true，确保HUD透明区域不遮挡RealityView的视觉。
• 非交互的HUD节点（比如背景）设置isUserInteractionEnabled = false，避免无意义拦截事件。
• 如需HUD完全覆盖时禁用RealityView交互，只需在HUDScene中添加一个全屏可交互背景节点，点击时不转发事件即可。

内容的提问来源于stack exchange，提问作者PKCLsoft