如何使用 ARKit iOS 缩放 .DAE 3D 模型

Question

我有一个带有 .scn 扩展名的 3D 模型。如何在没有来自 iOS 示例放置对象应用程序的 virtualobject 文件的情况下使用捏合手势进行缩放。

如果从 .obj 文件转换而来的 .scn 文件，捏合手势效果很好。但它不适用于 .dae 模型。

    func addPinchGestureToSceneView() {

        pinchGesture = UIPinchGestureRecognizer(target: self, action: #selector(scale))
        pinchGesture.scale = 1.0;
        pinchGesture.delegate = self
        self.sceneView.addGestureRecognizer(pinchGesture)
    }
  private func node(at position: CGPoint) -> SCNNode? {
        var hitTestOptions = [SCNHitTestOption: Any]()
        hitTestOptions[SCNHitTestOption.boundingBoxOnly] = true
        return sceneView.hitTest(position, options: hitTestOptions)
            .first(where: { self.getOnlyModelName(name: $0.node.name ?? "") == self.currentmodel.modelname})?
            .node

    }

 @objc func scale(_ gesture: UIPinchGestureRecognizer) {

        if self.currentmodel.isZoomEnabled == false{
            return
        }

        let location = gesture.location(in: sceneView)

        guard let node = node(at: location)else{return}

    //    guard let node = node(at: location) else  { return }

        switch gesture.state {
        case .began:
            originalScale = node.scale
            gesture.scale = CGFloat(node.scale.x)
            print("Begin:: \(originalScale)")
        case .changed:
            guard var originalScale = originalScale else { return }
            if gesture.scale > 2.0{
                return
            }
            originalScale.x = Float(gesture.scale)
            originalScale.y = Float(gesture.scale)
            originalScale.z = Float(gesture.scale)
            node.scale = originalScale
        case .ended:

            guard var originalScale = originalScale else { return }
            if gesture.scale > 2.0{
                return
            }
            originalScale.x = Float(gesture.scale)
            originalScale.y = Float(gesture.scale)
            originalScale.z = Float(gesture.scale)
            node.scale = originalScale
            gesture.scale = CGFloat(node.scale.x)

        default:
            gesture.scale = 1.0
            originalScale = nil
        }

Answer 1

当它是一个 dae 时，您可能需要尝试抓取在命中测试中捕获的节点的父节点。我有一个与 dae 类似的问题，通过让孩子的父母，甚至有时是孩子的祖父母来解决。