Question

我在添加到精灵工具包场景（ARKit项目）的SCNNode上启动了CAKeyframeAnimation。节点完美移动并正确触发动画开始/停止事件。但是，节点的位置值保持不变。

这是添加的节点，我检查过它只添加一次：

let plane = SCNPlane(width: 0.1, height: 0.1)
plane.firstMaterial?.diffuse.contents = UIImage(named: "fish_idle_1_\(GameManager.selectedFishSkin+1)")
fishNode = SCNNode(geometry: plane)
fishNode.name = "fish"
fishNode.constraints = [SCNBillboardConstraint()]
sceneView.scene.rootNode.addChildNode(fishNode)

动画启动，工作正常：

    let pendulumSwings = CAKeyframeAnimation(keyPath: "translation")

    pendulumSwings.duration = time
    pendulumSwings.repeatCount = 1
    pendulumSwings.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
    pendulumSwings.values = computedVectors
    pendulumSwings.delegate = self

    fishNode.removeAllAnimations()
    fishNode.addAnimation(pendulumSwings, forKey: nil)

委托代码：

extension Game: CAAnimationDelegate {
func animationDidStart(_ anim: CAAnimation) {
    guard let viewController = viewController else { return }
    guard let first = viewController.anchors.first else { return }
    guard let last = viewController.anchors.last else { return }
    print("START \(fishNode.position)")
    print("SCENE START \(viewController.sceneView.scene.rootNode.childNode(withName: "fish", recursively: false)!.position)")
}

func animationDidStop(_ anim: CAAnimation, finished flag: Bool) {
    guard let viewController = viewController else { return }
    guard let first = viewController.anchors.first else { return }
    guard let last = viewController.anchors.last else { return }
    print("END \(fishNode.position)")
    print("SCENE END \(viewController.sceneView.scene.rootNode.childNode(withName: "fish", recursively: false)!.position)")
}
}

两个4个打印语句都显示相同的值（取决于用例的值）：

START SCNVector3（x：0.386469185，y：-0.640618205，z：0.609007716）

我无法获得有关如何在场景上移动节点位置的任何反馈，因此我无法根据节点的位置执行任何计算。

Answer 1

看看您节点的.presentation属性。这是动画在节点上作用时节点的位置。

为您打印fishNode.presentation.position而不是fishNode.position

来自Apple文档：

表示节点的属性非常接近当前显示的节点版本。

https://developer.apple.com/documentation/scenekit/scnnode/1408030-presentation

CAKeyframeAnimation之后的SCNNode位置值不正确

1 个答案: