swift - 在 ARSCNView 中显示 "ARAnchor"

Question

在 ARKit 中，我们可以通过 .showFeaturePoints 类型属性可视化在 ARSession 中检测到的 Feature Points' Cloud:

self.sceneView.debugOptions = [ARSCNDebugOptions.showFeaturePoints]

此外，我们还可以显示坐标轴可视化，指示 AR 世界坐标系的位置和方向:

static let showWorldOrigin: SCNDebugOptions

但是可以在 ARSCNView 中显示 ARAnchors 吗？

如果是，我们该怎么做？

Answer 1

只是为了跟进@sj-r 和@Rickster 的评论。

@Rickster 谈到的关于 coordinateOrigin.scn 的示例代码可以在这里找到:Creating Face Based Experiences

这是我之前用来可视化 Axis 的一个小片段:

class BMOriginVisualizer: SCNNode {

    //----------------------
    //MARK: - Initialization
    //---------------------

    /// Creates An AxisNode To Vizualize ARAnchors
    ///
    /// - Parameter scale: CGFloat
    init(scale: CGFloat = 1) {

        super.init()

        //1. Create The X Axis
        let xNode = SCNNode()
        let xNodeGeometry = SCNBox(width: 1, height: 0.01, length: 0.01, chamferRadius: 0)
        xNode.geometry = xNodeGeometry
        xNodeGeometry.firstMaterial?.diffuse.contents = UIColor.red
        xNode.position = SCNVector3(0.5, 0, 0)
        self.addChildNode(xNode)

        //2. Create The Y Axis
        let yNode = SCNNode()
        let yNodeGeometry = SCNBox(width: 0.01, height: 1, length: 0.01, chamferRadius: 0)
        yNode.geometry = yNodeGeometry
        yNode.position = SCNVector3(0, 0.5, 0)
        yNodeGeometry.firstMaterial?.diffuse.contents = UIColor.green
        self.addChildNode(yNode)

        //3. Create The Z Axis
        let zNode = SCNNode()
        let zNodeGeometry = SCNBox(width: 0.01, height: 0.01, length: 1, chamferRadius: 0)
        zNode.geometry = zNodeGeometry
        zNodeGeometry.firstMaterial?.diffuse.contents = UIColor.blue
        zNode.position = SCNVector3(0, 0, 0.5)
        self.addChildNode(zNode)

        //4. Scale Our Axis
        self.scale = SCNVector3(scale, scale, scale)

    }


    required init?(coder aDecoder: NSCoder) { fatalError("Vizualizer Coder Not Implemented") }
}

可以这样初始化:

func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {

        let anchorVizualizer = BMOriginVisualizer(scale: 0.5)
        node.addChildNode(anchorVizualizer)

}

希望这对@sj-r 提供的答案的扩展有用。