SceneKit，缩放相机以适应节点

Question

您好，我有一个包含 3 个节点的非常简单的场景：

• 光
• 相机
• Stl

放置 STL 时，它非常小，因此用户必须大幅缩放相机。我想做的是以编程方式将相机缩放到适合的 STL 节点，但我不确定如何。

这是我目前所拥有的：

stlNode = .... // Custom node
lightNode = scene?.rootNode.childNode(withName: "omni", recursively: true)
        cameraNode = scene?.rootNode.childNode(withName: "camera", recursively: true)

        cameraNode.constraints  = [SCNLookAtConstraint(target: stlNode)]
// Zoom to fit the stlNode here.
        scene?.rootNode.addChildNode(stlNode)

Answer 1

您可以尝试创建一个 cameraClass，然后添加 zoomIn()、zoomOut() 函数以便您进行调整。您还可以稍微扩展您的节点，看看是否有帮助。

var cameraEye = SCNNode()
var cameraFocus = SCNNode()

...
init()
    {
        cameraEye.name = "Camera Eye"
        cameraFocus.name = "Camera Focus"

        cameraFocus.isHidden = true
        cameraFocus.position  =  SCNVector3(x: 0, y: 0, z: 0)

        cameraEye.camera = SCNCamera()
        cameraEye.constraints = []
        cameraEye.position = SCNVector3(x: 0, y: 15, z: 0.1)

        let vConstraint = SCNLookAtConstraint(target: cameraFocus)
        vConstraint.isGimbalLockEnabled = true
        cameraEye.constraints = [vConstraint]
    }
// Add your camera nodes
gameNodes.addChildNode(camera.cameraEye)
gameNodes.addChildNode(camera.cameraFocus)

ZoomIn()/zoomOut() 只是一个调整距离的功能。