RealityKit 不会显示多个 DirectionalLight

Question

我正在尝试在 RealityKit 中创建一个简单的 3D 场景，其中有两盏灯从相反的两侧照亮网格。一切似乎都在工作，但两个灯不会同时工作。如果我注释掉 light01，则 light02 会正常显示。显然，从项目类型来看，您可以看出我在这方面还很陌生。我错过了什么？

func makeUIView(context: Context) -> ARView {

    //Configure ARView
    let arView = ARView(frame: .zero, cameraMode: .nonAR, 
                   automaticallyConfigureSession: true)
    
    //Set background color
    arView.environment.background = .color(.black)
    
    let light01 = DirectionalLight()
    light01.light.color = .red
    light01.light.intensity = 30000
    light01.light.isRealWorldProxy = true
    light01.shadow?.maximumDistance = 10.0
    light01.shadow?.depthBias = 5.0
    light01.orientation = simd_quatf(angle: -.pi/1.5, axis: [0,1,0])
    let light01Anchor = AnchorEntity(world: [0, 20, 0])
    light01Anchor.addChild(light01)
    arView.scene.addAnchor(light01Anchor)
    
    //NOT WORKING
    let light02 = DirectionalLight()
    light02.light.color = .green
    light02.light.intensity = 20000
    light02.light.isRealWorldProxy = true
    light02.shadow?.maximumDistance = 10.0
    light02.shadow?.depthBias = 5.0
    light02.orientation = simd_quatf(angle: .pi/1.5, axis: [0,1,0])
    let light02Anchor = AnchorEntity(world: [0, 40, 0])
    light02Anchor.addChild(light02)
    arView.scene.addAnchor(light02Anchor)      
    
    //Create plane for floor
    let floorMesh = MeshResource.generatePlane(width: 10, depth: 10)
    let floorMaterial = SimpleMaterial(color: .white, isMetallic: false)
    let floorEntity = ModelEntity(mesh: floorMesh, 
                             materials: [floorMaterial])
    let floorAnchor = AnchorEntity(world: [0, 0, 0])
    floorAnchor.addChild(floorEntity)
    arView.scene.addAnchor(floorAnchor)      

    let sphereMesh = MeshResource.generateSphere(radius: 1.5)
    let sphereMaterial = SimpleMaterial(color: .white, 
                                    roughness: 0.9, 
                                   isMetallic: false)
    let sphereEntity = ModelEntity(mesh: sphereMesh, 
                              materials: [sphereMaterial])
    let sphereAnchor = AnchorEntity(world: [0, 1.5, -4])
    sphereAnchor.addChild(sphereEntity)
    arView.scene.addAnchor(sphereAnchor)
            
    //Camera
    let camera = PerspectiveCamera()
    let cameraAnchor = AnchorEntity(world: [0, 1, 1])
    cameraAnchor.addChild(camera)
    arView.scene.addAnchor(cameraAnchor)
    
    return arView
}

Answer 1

关于 RealityKit 2.0 中的 DirectionalLight

RealityKit 场景最多可以包含 nine lights。其中八个可能是不同类型的动态光——PointLights、SpotLights 和 DirectionalLight，其中一个是 image-based 光 (IBL)。但是，RealityKit 仅支持每个场景 ONE DirectionalLight（a.k.a。虚拟太阳）。

除上述之外，需要注意的是DirectionalLight在RealityKit场景中的位置无关紧要 DirectionalLight 有 .isRealWorldProxy 个实例属性，如果设置为 true，它会在虚拟内容上投射阴影而不照亮场景中的任何东西。您可以使用它在接受动态照明的遮挡材料上创建阴影。

RealityKit 不会显示多个 DirectionalLight

RealityKit won't show more than one DirectionalLight

swift

realitykit

关于 RealityKit 2.0 中的 DirectionalLight