ARKit–使用CALayer无法正确地在SCNNode中加载GIF图像

我正在开发一个3D模型的AR应用程序。

点击子节点后，我将通过使用CALayer创建动画并将其加载到diffuse.contents中（通过遵循此线程）来显示GIF图像将CALayer的内容设置为动画GIF？

let animation : CAKeyframeAnimation = createGIFAnimation(url: gifImageURL!)!
let layer = CALayer()
layer.bounds = CGRect(x: 0, y: 0, width:600, height:200)
layer.add(animation, forKey: "contents")

let newMaterial = SCNMaterial()
newMaterial.isDoubleSided = true
newMaterial.diffuse.cOntents= layer
let plane = SCNPlane(width: 5, height: 5)
plane.materials = [newMaterial]
let node = SCNNode(geometry: plane)
self.sceneView.scene.rootNode.addChildNode(node)

我能够在SCNNode中渲染gif图像，但它只显示其中的四分之一（GIF的最右下半部分仅可见）。我尝试了以下步骤来纠正此问题，但仍然徒劳。

更改平面的宽度/高度

更改CALayer的界限

尝试使用不同尺寸的gif图像

任何人都可以帮助我如何使用CALayer在SCNPlane中渲染完整的gif图像。

作为一种解决方法，我按照以下过程正确加载了GIF：

let plane = SCNPlane(width: 2, height: 2)

let bundleURL = Bundle.main.url(forResource: "engine", withExtension: "gif")
let animation : CAKeyframeAnimation = createGIFAnimation(url: bundleURL!)!
let layer = CALayer()
layer.bounds = CGRect(x: 0, y: 0, width: 900, height: 900)

layer.add(animation, forKey: "contents")
let tempView = UIView.init(frame: CGRect(x: 0, y: 0, width: 900, height: 900))
tempView.layer.bounds = CGRect(x: -450, y: -450, width: tempView.frame.size.width, height: tempView.frame.size.height)
tempView.layer.addSublayer(layer)

let newMaterial = SCNMaterial()
newMaterial.isDoubleSided = true
newMaterial.diffuse.cOntents= tempView.layer
plane.materials = [newMaterial]
let node = SCNNode(geometry: plane)
node.name = "engineGif"
let gifImagePosition = SCNVector3Make((self.virtualObjectInteraction.selectedObject?.childNodes[0].position.x)! + 2, 
                                      (self.virtualObjectInteraction.selectedObject?.childNodes[0].position.y)! + 4, 
                                      (self.virtualObjectInteraction.selectedObject?.childNodes[0].position.z)! - 2)
node.position = gifImagePosition
self.virtualObjectInteraction.selectedObject?.childNodes[0].addChildNode(node)

在createGIFAnimation创建所需动画的地方，

func createGIFAnimation(url:URL) -> CAKeyframeAnimation? {

    guard let src = CGImageSourceCreateWithURL(url as CFURL, nil) else { return nil }
    let frameCount = CGImageSourceGetCount(src)

    // Total loop time
    var time : Float = 0

    // Arrays
    var framesArray = [AnyObject]()
    var tempTimesArray = [NSNumber]()

    // Loop
    for i in 0..