SceneKit 进口的 COLLADA 盒子未“点亮”

Question

我有一个 SceneKit 项目，在场景视图中有两个对象。第一个对象是通过 SCNPlane 创建的平面。第二个对象是在 Blender 中创建的一个简单的盒子。在代码中，我设置了环境和全向照明。它的灯光效果适用于飞机：

但是，当我在飞机顶部添加盒子时，灯光效果在飞机上起作用，但从 COLLADA 文件导入的盒子却不起作用：

我怀疑问题与法线有关，但我不确定。有没有人通过 SceneKit 导入 DAE 遇到过这种情况？灯光和物体的设置代码是这样的：

private func setupAmbientLight() {

    // setup ambient light source
    let ambientLightNode = SCNNode()
    ambientLightNode.light = SCNLight()
    ambientLightNode.light!.type = SCNLight.LightType.ambient
    ambientLightNode.light!.color = NSColor(white: 0.35, alpha: 1.0).cgColor

    // add to scene
    guard let scene = sceneView.scene else {

        return
    }
    scene.rootNode.addChildNode(ambientLightNode)
}

private func setupOmniDirectionalLight() {

    // initialize noe
    let omniLightNode = SCNNode()
    // assign light
    omniLightNode.light = SCNLight()
    // set type
    omniLightNode.light!.type = SCNLight.LightType.omni
    // color and position
    omniLightNode.light!.color = NSColor(white: 0.56, alpha: 1.0).cgColor
    omniLightNode.position = SCNVector3Make(0.0, 2000.0, 0.0)

    // add to scene
    guard let scene = sceneView.scene else {

        return
    }
    scene.rootNode.addChildNode(omniLightNode)
}

private func setupPlane() {

    // create plane geometry with size and material properties
    let myPlane = SCNPlane(width: planeSideLength, height: planeSideLength)
    myPlane.firstMaterial!.diffuse.contents = NSColor.orange.cgColor
    myPlane.firstMaterial!.specular.contents = NSColor.white.cgColor

    // intialize node
    let planeNode = SCNNode()
    // assign plane geometry to the node
    planeNode.geometry = myPlane

    // rotate -90.0 about the x-axis
    let rotMat = SCNMatrix4MakeRotation(-CGFloat(M_PI/2.0), 1.0, 0.0, 0.0)
    planeNode.transform = rotMat
    planeNode.position = SCNVector3Make(0.0, 0.0, 0.0)

    // setup the node's physics body property
    planeNode.physicsBody = SCNPhysicsBody(type: .static, shape: SCNPhysicsShape(geometry: myPlane, options: nil))
    planeNode.physicsBody!.categoryBitMask = PhysicsMask3DOF.plane.rawValue

    // add to scene
    guard let scene = sceneView.scene else {

        return
    }

    scene.rootNode.addChildNode(planeNode)
}

private func setupRobot() {

    guard let mainScene = sceneView.scene else {

        return
    }

    let bundle = Bundle.main

    guard let url = bundle.url(forResource: "robot.scnassets/test_cube", withExtension: "dae") else {

        return
    }

    var cubeScene: SCNScene?

    do {

        try cubeScene = SCNScene.init(url: url, options: nil)
    }
    catch {

        return
    }

    guard let cubeNode = cubeScene!.rootNode.childNode(withName: "Cube", recursively: true) else {

        return
    }

    cubeNode.removeFromParentNode()
    cubeNode.scale = SCNVector3Make(2000.0, 2000.0, 2000.0)
    cubeNode.geometry!.firstMaterial!.diffuse.contents = NSColor.blue.cgColor
    cubeNode.geometry!.firstMaterial!.specular.contents = NSColor.white.cgColor

    mainScene.rootNode.addChildNode(cubeNode)
}

更新：

所以我注释了从 DAE 导入盒子的代码，而是添加了通过 SCNBox 创建盒子的代码，灯光效果似乎可以工作：

Answer 1

呃，盒子是 [2000 x 2000 x 2000]，它的节点在 (0, 0, 0)。全光源节点的位置为 (0, 2000, 0)。只需要向上移动光源。这就引出了一个问题，当我通过 SCNBox 函数而不是从 DAE 文件导入创建具有相同尺寸的盒子时，为什么盒子会正确点亮