Question

我想从SCNNode中检索屏幕坐标，这样我就可以在SpriteKit-overlay中使用这些坐标。该节点是子节点。当我旋转父节点的pivot时，projectPoint返回乱码结果。

SCNScene：

class ScenekitScene:SCNScene {
    override init() {
        super.init()

        let nodeCamera = SCNNode()
        nodeCamera.camera = SCNCamera()
        rootNode.addChildNode(nodeCamera)

        let geoPyramid = SCNPyramid(width: 0.2, height: 0.5, length: 0.2)
        let nodeCenterOfUniverse = SCNNode(geometry: geoPyramid)
        nodeCenterOfUniverse.position = SCNVector3(0, 0, -5)
        nodeCenterOfUniverse.pivot = SCNMatrix4MakeRotation(CGFloat.pi/4, 0.0, 0.0, 1.0)
        rootNode.addChildNode(nodeCenterOfUniverse)

        let geoSphere = SCNSphere(radius: 0.3)
        let nodePlanet = SCNNode(geometry: geoSphere)
        nodePlanet.name = "planet"
        nodePlanet.position = SCNVector3(2, 0, 0)
        nodeCenterOfUniverse.addChildNode(nodePlanet)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

SCNSceneRenderDelegate：

extension ViewController:SCNSceneRendererDelegate {
    func renderer(_ renderer: SCNSceneRenderer, didRenderScene scene: SCNScene, atTime time: TimeInterval) {
        if let planet = scene.rootNode.childNode(withName: "planet", recursively: true) {
            let position = planet.convertPosition(planet.position, to: scene.rootNode)
            let screencoords = renderer.projectPoint(position)
            print (screencoords)

            # result:
            # SCNVector3(x: 461.913848876953, y: 2.58612823486328, z: 0.808080852031708)
            # y should clearly be more to the center of the screen somewhere between 100-200
        }
    }
}

有谁知道如何获得正确的屏幕坐标？

Answer 1

看起来世界坐标中的行星位置不正确。当我手动计算行星位置时，我会得到不同的结果，而projectPoints的工作方式与宣传的一样。 [我可能会发布一个关于worldTransform的不同问题]。

static class starton implements ActionListener {

    //...

    public void actionPerformed(ActionEvent e) {
        button.setText("Press A Button");
        button.setSize(button.getPreferredSize());
        button.addKeyListener(...);
        button.removeActionListener(this);
    }
}

旋转SCNNode.pivot后SceneKit projectPoint不正确

1 个答案: