如何在 Swift UI 中添加 3D 形状？

Question

我想知道如何在 swift UI 中添加 3D 形状（例如球体）

我尝试添加一个场景并在 swift UI 中使用它，但收到一条错误消息

//SceneKit

class myscene: SCNScene{
 override init(){
     super.init()
 }
 required init?(coder: NSCoder) {
     fatalError("init(coder: ) has not been implemented")
 }
}

//Swift UI 

struct ContentView: View {
 var body: some View {

     let sphere = SCNSphere(radius: 2.0)
     sphere.firstMaterial?.diffuse.contents = UIColor.blue
     let spherenode = SCNNode(geometry: sphere)
     spherenode.position = SCNVector3(x: 0.0, y: 3.0, z: 0.0)
 }
}

网上的错误消息var body: some View {如下：

Function declares an opaque return type, but has no return statements in its body from which to infer an underlying type

请帮我解决这个问题......

Answer 1

这是最简单的代码，演示如何使用球体设置 SceneKit 场景。希望能帮助到你。

import SwiftUI
import SceneKit

struct SceneKitView: UIViewRepresentable {
    func makeUIView(context: UIViewRepresentableContext<SceneKitView>) -> SCNView {
        let sceneView = SCNView()
        sceneView.scene = SCNScene()
        sceneView.allowsCameraControl = true
        sceneView.autoenablesDefaultLighting = true
        sceneView.backgroundColor = UIColor.black

        let sphere = SCNSphere(radius: 2.0)
        sphere.firstMaterial?.diffuse.contents = UIColor.blue
        let spherenode = SCNNode(geometry: sphere)
        spherenode.position = SCNVector3(x: 0.0, y: 3.0, z: 0.0)

        sceneView.scene?.rootNode.addChildNode(spherenode)
        return sceneView
    }
    
    func updateUIView(_ uiView: SCNView, context: UIViewRepresentableContext<SceneKitView>) {
        
    }
    
    typealias UIViewType = SCNView
}

struct DemoSceneKit: View {
    var body: some View {
        SceneKitView()
    }
}

struct DemoSceneKit_Previews: PreviewProvider {
    static var previews: some View {
        DemoSceneKit()
    }
}