将UIView设置为SCNMaterial内容

Question

我正在尝试使用带有Arkit 3D空间的UIView。我看到了一些示例，这些示例要求UIView或UIView的层设置为SCNMaterial对象的扩散内容。这不像我预料的那样有效。我只看到视图的框架，但它中的子视图没有添加，也没有看到图层上的角半径。

func setupBillBoard() {
    let view = PlayerView(frame: CGRect(x: 0, y: 0, width: 70, height: 40))
    view.backgroundColor = .red
    view.layer.cornerRadius = 14

    let material = SCNMaterial()
    material.diffuse.contents = view.asImage()
    material.isDoubleSided = true

    let plane = SCNPlane(width: 1, height: 1)
    plane.materials = [material]

    let node = SCNNode()
    node.geometry = plane
    node.position = SCNVector3(box.x, box.y + 0.3, box.z - 0.4)
    node.scale = SCNVector3(0.4, 0.4, 0.4)

    self.billBoardNode = node
}

视图扩展以将UIView转换为图像捕获

    extension UIView {
        func asImage() -> UIImage {
            let renderer = UIGraphicsImageRenderer(bounds: bounds)
            return renderer.image { rendererContext in
                layer.render(in: rendererContext.cgContext)
            }
        }
    }

到目前为止，我在现场只看到了一个红色的方形视图，没有别的了。

自定义类代码:附件图像中的https://www.paste.org/106551 Xib

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Answer 1

这是我布置地雷的方法，它很好用。您应该能够在viewDidLoad中复制和粘贴该函数，然后您将看到一个红色的圆圈。您还可以使用UIImageView而不是UIView。

在创建自定义UIView之后，在将其添加到SCNMaterial之前调用yourView.layoutIfNeeded()。

您也可以在几何上设置角半径：plane.cornerRadius = 0.015，就像我在createAndPositionGrayNode()中所做的那样

override func viewDidLoad() {
    super.viewDidLoad()

    createAndPositionRedCircleNode()

    // or try it with an imageView, comment out the line above
    // createAndPositionGrayNode()
}

func createAndPositionRedCircleNode() {

    let redImage = UIColor.red.imageRepresentation

    let myView = UIView()
    myView.frame = CGRect(x: 0, y: 0, width: 250, height: 250)
    myView.layer.contents = redImage.cgImage
    myView.layoutIfNeeded() // <-- myView.layoutIfNeeded() called here
    myView.layer.contentsGravity = CALayerContentsGravity.resizeAspectFill
    myView.layer.contentsScale = UIScreen.main.scale
    myView.layer.masksToBounds = true
    myView.layer.cornerRadius = myView.frame.width / 2

    let convertedImage = myView.asImage()

    let material = SCNMaterial()
    material.diffuse.contents = convertedImage

    let plane = SCNPlane(width: 0.15, height: 0.15)
    plane.materials = [material]
    plane.firstMaterial?.isDoubleSided = true

    let redNode = SCNNode(geometry: plane)
    redNode.name = "redNode"
    redNode.position = SCNVector3(0.0, 0.2, -0.7)
    sceneView.scene.rootNode.addChildNode(redNode)
}

func createAndPositionGrayNode() {

    let lightGrayImage = UIColor.lightGray.imageRepresentation

    let imageView = UIImageView()
    imageView.frame = CGRect(x: 0, y: 0, width: 250, height: 250)
    imageView.image = lightGrayImage
    imageView.contentMode = .scaleAspectFit
    imageView.backgroundColor = .clear
    imageView.layer.masksToBounds = true

    let material = SCNMaterial()
    material.diffuse.contents = imageView.image

    let plane = SCNPlane(width: 0.4, height: 0.4)
    plane.materials = [material]
    plane.firstMaterial?.isDoubleSided = true
    plane.cornerRadius = 0.015 // <-- geometry cornerRadius set here

    let grayNode = SCNNode(geometry: plane)
    grayNode.name = "grayNode"
    grayNode.position = SCNVector3(0.0, 0.2, -0.7)
    sceneView.scene.rootNode.addChildNode(grayNode)
}

extension UIView {
    func asImage() -> UIImage {
        let renderer = UIGraphicsImageRenderer(bounds: bounds)
            return renderer.image { rendererContext in
            layer.render(in: rendererContext.cgContext)
        }
    }
}