Ios 如何在用户点击的位置使用SceneKit渲染球体

♪取消投影点♪

要在预期位置呈现点 node ，请使用以下方法.不要忘记，您正在以透视投影的方式查看场景.取消投影Z坐标为0.0的点将返回near clipping plane上的一个点.取消投影Z坐标为1.0的点将返回far clipping plane上的一个点.

import SceneKit

class GameViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()            
        let sceneView = self.view as! SCNView
        sceneView.scene = SCNScene()
        sceneView.backgroundColor = UIColor.black
                
        let cameraNode = SCNNode()
        cameraNode.camera = SCNCamera()
        cameraNode.simdPosition = simd_float3(0, 0, 1)
        sceneView.scene?.rootNode.addChildNode(cameraNode)
        
        let tapGesture = UITapGestureRecognizer(target: self,
                                                action: #selector(tap))
        sceneView.addGestureRecognizer(tapGesture)
    }

    @objc func tap(_ gestureRecognizer: UITapGestureRecognizer) {
        let scnView = self.view as! SCNView
        
        let geo = SCNSphere(radius: 0.01)
        geo.firstMaterial?.diffuse.contents = UIColor.white
        let dotNode = SCNNode(geometry: geo)

        let point = gestureRecognizer.location(in: scnView)
        let unprojected = scnView.unprojectPoint(.init(point.x, point.y, 0))
 
        dotNode.position = SCNVector3(unprojected.x, unprojected.y, -0.01)
        scnView.scene?.rootNode.addChildNode(dotNode)
    }
}

要在正交投影中运行摄影机，请使用:

cameraNode.camera?.usesOrthographicProjection = true