Ios SceneKit中的连续变形动画

我很难在SceneKit中通过不同的变形目标设置动画。 我有一个变形目标数组，我想通过一个循环来显示它们，每个变形目标之间都有一个动画

从一个几何体到另一个几何体，这很容易。 在中，有一个示例可用于一个变形几何体（morpher.weights[0]）：

我想做的是，为变形设置动画。我尝试为每个目标设置几个动画。但在完成第一个动画后，第一个目标的权重再次设置为0

override func viewDidLoad() {
    super.viewDidLoad()

    // create a new scene
    let scene = SCNScene()

    let vbasic_geom: [Vertex] = [
        [ [0, 0, 0],      [+1.0, +0.0, +0.0] ],
        [ [0, 2, 0],      [+1.0, +0.0, +0.0] ],
        [ [2, 2, 0],      [+1.0, +0.0, +0.0] ]
    ]

    let vmorph1: [Vertex] = [
        [ [0, 0, 0],      [+1.0, +0.0, +0.0] ],
        [ [0, 4, 0],      [+1.0, +0.0, +0.0] ],
        [ [2, 2, 0],      [+1.0, +0.0, +0.0] ]
    ]

    let vmorph2: [Vertex] = [
        [ [0, 0, 0],      [+1.0, +0.0, +0.0] ],
        [ [0, 2, 0],      [+1.0, +0.0, +0.0] ],
        [ [4, 2, 0],      [+1.0, +0.0, +0.0] ]
    ]


    let basic_geom = gen_geometry(vbasic_geom)

    let morph1 = gen_geometry(vmorph1)

    let morph2 = gen_geometry(vmorph2)


    let morpher = SCNMorpher()
    morpher.targets = [morph1, morph2]

    let object = SCNNode(geometry: basic_geom)
    object.morpher = morpher

    //needed for model-layer refresh; implicit animation
    morpher.setWeight(1.0, forTargetAtIndex: 0)
    morpher.setWeight(1.0, forTargetAtIndex: 1)

    //set up animations
    let animation = CABasicAnimation(keyPath: "morpher.weights[0]")
    animation.fromValue = 0.0
    animation.toValue = 1.0
    animation.duration = 5
    animation.beginTime = 0.0
    animation.removedOnCompletion = false

    let animation2 = CABasicAnimation(keyPath: "morpher.weights[1]")
    animation2.fromValue = 0.0;
    animation2.toValue = 1.0
    animation2.duration = 5
    animation2.beginTime = 5.0
    animation.removedOnCompletion = false

    let animationgroup = CAAnimationGroup()
    animationgroup.duration = 10.0
    animationgroup.autoreverses = false
    animationgroup.repeatCount = 10000;

    animationgroup.animations = [animation, animation2]

    object.addAnimation(animationgroup, forKey: "morpher.weights")

    scene.rootNode.addChildNode(object)

GIF

尝试了几种解决方案，但我从未成功：

• 也许可以将`关键路径：“morpher.weights[0]”更改为` morpher.weights'，并将from和toValues设置为类似数组的值。包括更改valueFunction

• 由于动画发生在表示层上，因此必须将已设置动画的特性保留为完成值。它尝试了“removedOnCompletion”，但似乎不起作用

有人有线索或解决办法吗

---

如果有必要的话，我可以发布一个链接到整个代码——这里不需要它。

这是CAAnimation的一个常见问题——不仅仅是SceneKit：默认情况下，完成时会删除显式动画，并且呈现值会重置为模型值（显式动画永远不会修改该值）。 有两种解决方案：

改为使用隐式动画（带有 将触发下一个动画的完成块）

将removedOnCompletion设置为NO，并将fillMode设置为FillForward

（可选）对于#2：您可以将代理设置为动画，并在将modelValue与presentationValue同步后删除animationDidStop中的动画

override func viewDidLoad() {
    super.viewDidLoad()

    // create a new scene
    let scene = SCNScene()

    let vbasic_geom: [Vertex] = [
        [ [0, 0, 0],      [+1.0, +0.0, +0.0] ],
        [ [0, 2, 0],      [+1.0, +0.0, +0.0] ],
        [ [2, 2, 0],      [+1.0, +0.0, +0.0] ]
    ]

    let vmorph1: [Vertex] = [
        [ [0, 0, 0],      [+1.0, +0.0, +0.0] ],
        [ [0, 4, 0],      [+1.0, +0.0, +0.0] ],
        [ [2, 2, 0],      [+1.0, +0.0, +0.0] ]
    ]

    let vmorph2: [Vertex] = [
        [ [0, 0, 0],      [+1.0, +0.0, +0.0] ],
        [ [0, 2, 0],      [+1.0, +0.0, +0.0] ],
        [ [4, 2, 0],      [+1.0, +0.0, +0.0] ]
    ]


    let basic_geom = gen_geometry(vbasic_geom)

    let morph1 = gen_geometry(vmorph1)

    let morph2 = gen_geometry(vmorph2)


    let morpher = SCNMorpher()
    morpher.targets = [morph1, morph2]

    let object = SCNNode(geometry: basic_geom)
    object.morpher = morpher

    //needed for model-layer refresh; implicit animation
    morpher.setWeight(1.0, forTargetAtIndex: 0)
    morpher.setWeight(1.0, forTargetAtIndex: 1)

    //set up animations
    let animation = CABasicAnimation(keyPath: "morpher.weights[0]")
    animation.fromValue = 0.0
    animation.toValue = 1.0
    animation.duration = 5
    animation.beginTime = 0.0
    animation.removedOnCompletion = false

    let animation2 = CABasicAnimation(keyPath: "morpher.weights[1]")
    animation2.fromValue = 0.0;
    animation2.toValue = 1.0
    animation2.duration = 5
    animation2.beginTime = 5.0
    animation.removedOnCompletion = false

    let animationgroup = CAAnimationGroup()
    animationgroup.duration = 10.0
    animationgroup.autoreverses = false
    animationgroup.repeatCount = 10000;

    animationgroup.animations = [animation, animation2]

    object.addAnimation(animationgroup, forKey: "morpher.weights")

    scene.rootNode.addChildNode(object)