关于图像标记检测,我只想使用ARKit
在该标记边界内播放正在行走的家伙的动画。为此,我想找出那个3D对象在标记上行走时的位置。动画是使用外部3D创作工具创建的,并作为.scnassets
文件保存在.dae
中。我添加了节点并使用以下代码开始动画:
func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
if let imageAnchor = anchor as? ARImageAnchor {
DispatchQueue.main.async {
//let translation = imageAnchor.transform.columns.3
let idleScene = SCNScene(named: "art.scnassets/WalkAround/WalkAround.dae")!
// This node will be parent of all the animation models
let node1 = SCNNode()
// Add all the child nodes to the parent node
for child in idleScene.rootNode.childNodes {
node1.addChildNode(child)
}
node1.scale = SCNVector3(0.2, 0.2, 0.2)
let physicalSize = imageAnchor.referenceImage.physicalSize
let size = CGSize(width: 500, height: 500)
let skScene = SKScene(size: size)
skScene.backgroundColor = .white
let plane = SCNPlane(width: self.referenceImage!.physicalSize.width, height: self.referenceImage!.physicalSize.height)
let material = SCNMaterial()
material.lightingModel = SCNMaterial.LightingModel.constant
material.isDoubleSided = true
material.diffuse.contents = skScene
plane.materials = [material]
let rectNode = SCNNode(geometry: plane)
rectNode.eulerAngles.x = -.pi / 2
node.addChildNode(rectNode)
node.addChildNode(node1)
self.loadAnimation(withKey: "walking", sceneName: "art.scnassets/WalkAround/SambaArmtr", animationIdentifier: "SambaArmtr-1")
}
}
}
func loadAnimation(withKey: String, sceneName:String, animationIdentifier:String) {
let sceneURL = Bundle.main.url(forResource: sceneName, withExtension: "dae")
let sceneSource = SCNSceneSource(url: sceneURL!, options: nil)
if let animationObject = sceneSource?.entryWithIdentifier(animationIdentifier, withClass: CAAnimation.self) {
// The animation will only play once
animationObject.repeatCount = 1
}
}
我尝试在以下两种方法中使用node.presentation.position
来获取对象的当前位置。
func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval)
// Or
func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor)
如果一旦动画开始后我不再移动设备,那么这些方法将不会被调用,直到我获得相同的节点位置为止。那就是为什么我没有走错地方。还是在ARKit中进行动画时有什么方法可以获取对象的当前位置?
我不知道如何在嵌入式动画中获取当前帧。话虽如此,嵌入在模型中的动画使用CoreAnimation来运行动画。您可以使用CAAimationDelegate
收听动画的开始/结束事件并运行计时器。计时器将为您提供最佳的动画估计时间。
参考:SceneKit动画内容文档:https://developer.apple.com/documentation/scenekit/animation/animating_scenekit_content
CAAnimationDelegate文档:https://developer.apple.com/documentation/quartzcore/caanimationdelegate