Swift SceneKit 设置最大/最小相机变焦

Question

我创建了一个球体，并希望为默认相机控制设置缩放的最大值和最小值 (sceneView.allowsCameraControl = true)

如何设置用户可以缩放球体的最大/最小值？

编辑： 我在SCNCamera 中找到了zNear 和zFar 属性，但我使用正交投影，在这个投影中zNear 和zFar 没有工作（

// Set scene settings
sceneView.scene = scene

cameraOrbit = SCNNode()
cameraNode = SCNNode()
cameraNode.name = "camera"
camera = SCNCamera()

// camera stuff
camera.usesOrthographicProjection = true
camera.orthographicScale = 5
camera.zNear = 1
camera.zFar = 100


// initially position is far away as we will animate moving into the globe
cameraNode.position = SCNVector3(x: 0, y: 0, z: 50)
cameraNode.camera = camera
cameraOrbit = SCNNode()
cameraOrbit.addChildNode(cameraNode)
scene.rootNode.addChildNode(cameraNode)

// Material
let blueMaterial = SCNMaterial()
blueMaterial.diffuse.contents = UIImage(named: "earth2")
blueMaterial.shininess = 0.05
blueMaterial.multiply.contents = UIColor(displayP3Red: 0.7, green: 0.7, blue: 0.7, alpha: 1.0)

let sphere = SCNSphere(radius: 2)
sphere.segmentCount = 300
sphere.firstMaterial?.diffuse.contents = UIColor.red
earthNode = SCNNode(geometry: sphere)
earthNode.name = "sphere"
earthNode.geometry?.materials = [blueMaterial]
scene.rootNode.addChildNode(earthNode)
earthNode.rotation = SCNVector4(0, 1, 0, 0)

let lightNode = SCNNode()
let light = SCNLight()
light.type = .ambient
light.intensity = 200

lightNode.light = light
scene.rootNode.addChildNode(lightNode)

sceneView.allowsCameraControl = true
sceneView.backgroundColor = UIColor.clear
sceneView.cameraControlConfiguration.allowsTranslation = true
sceneView.cameraControlConfiguration.rotationSensitivity = 0.4

Answer 1

不要使用allowCameraControl - 它的功能有限。

创建您自己的相机类：

class Camera
{
    var data = Data.sharedInstance
    var util = Util.sharedInstance
    var gameDefaults = Defaults()
    
    var cameraEye = SCNNode()
    var cameraFocus = SCNNode()
        
    var centerX: Int = 100
    var strafeDelta: Float = 0.8
    var zoomLevel: Int = 35
    var zoomLevelMax: Int = 35              // Max number of zoom levels
    
    //********************************************************************
    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]
    }
    //********************************************************************
    func reset()
    {
        centerX = 100
        cameraFocus.position  =  SCNVector3(x: 0, y: 0, z: 0)
        cameraEye.constraints = []
        cameraEye.position = SCNVector3(x: 0, y: 32, z: 0.1)
        cameraFocus.position = SCNVector3Make(0, 0, 0)
        
        let vConstraint = SCNLookAtConstraint(target: cameraFocus)
        vConstraint.isGimbalLockEnabled = true
        cameraEye.constraints = [vConstraint]
    }
    //********************************************************************
    func strafeRight()
    {
        if(centerX + 1 < 112)
        {
            centerX += 1
            cameraEye.position.x += strafeDelta
            cameraFocus.position.x += strafeDelta
        }
    }
    //********************************************************************
    func strafeLeft()
    {
        if(centerX - 1 > 90)
        {
            centerX -= 1
            cameraEye.position.x -= strafeDelta
            cameraFocus.position.x -= strafeDelta
        }
    }
    //********************************************************************
}

这个例子有扫射，但缩放是类似的——只是将眼睛移近目标。将最远距离设置为默认值，然后根据百分比或 lerp 将眼睛移近。

编辑

//**************************************************************************
    func dragBegins(vRecognizer: UIPanGestureRecognizer)
    {
        if(data.gameState == .run)
        {
            if(vRecognizer.numberOfTouches == 2) { dragMode = .strafe }
        }
    }
    //**************************************************************************
    func dragChanges(vRecognizer: UIPanGestureRecognizer)
    {
        if(data.gameState == .run)
        {
            if(dragMode == .strafe && vRecognizer.numberOfTouches == 1)
            {
                dragMode = .none
                return
            }
            
            switch(dragMode)
            {
            case .strafe:
                gNodes.camera.strafe(vX: Float(currentLocation.x), vY: Float(currentLocation.y))
                break
            case .none:
                break
            default:
                break
            }
        }
    }
    //**************************************************************************
    func dragEnds(vRecognizer: UIPanGestureRecognizer)
    {
        if(data.gameState == .run)
        {
            switch(dragMode)
            {
            case .strafe:
                break
            default:
                break
            }
        }
        dragMode = .none
    }