Question

我一直在尝试使用SKCameraNode，但我找不到任何关于用它创建视差效果的信息。

我们假设我添加了上面的代码，并在behindNode下方添加baseNode。然后我为我的相机制作动画。

let behindNode = SKNode()
addChild(behindNode)

let blueSquare = SKSpriteNode(color: SKColor.blueColor(), size: CGSize(width: 80, height: 80))
blueSquare.position = CGPoint(x: size.width/2+40, y: size.height/2+40)
behindNode.addChild(blueSquare)

let baseNode = SKNode()
addChild(baseNode)

let redSquare = SKSpriteNode(color: SKColor.redColor(), size: CGSize(width: 80, height: 80))
redSquare.position = CGPoint(x: size.width/2, y: size.height/2)
baseNode.addChild(redSquare)


let cameraNode = SKCameraNode()
camera = cameraNode
addChild(camera!)
camera!.position = redSquare.position

cameraNode.runAction(SKAction.sequence([
    SKAction.waitForDuration(1),
    SKAction.moveBy(CGVector(dx: 100, dy: 100), duration: 3),
    SKAction.moveBy(CGVector(dx: -100, dy: 100), duration: 1),
    SKAction.moveBy(CGVector(dx: 100, dy: -100), duration: 1)
]))

当相机移动时，我需要蓝色方块相对于红色方块以较慢的速度移动..我希望cameranode有相对位置字典或其他东西，但它不会......

Answer 1

我创建了一个不处理秒或帧的解决方案。

您可以创建SKCameraNode的子类，并使用Swift的didSet（）方法，该方法在更改类变量后调用。在我们的例子中，我们想要监听摄像机节点位置变量的变化。

class CameraNodeParallax:SKCameraNode{

override var position : CGPoint {
    didSet {  
       // Move our backgrounds
    }
}

我们还希望创建一个包含所有视差背景节点的数组，以及一个包含相对于相机移动速度的相应移动速度的数组。

var backgroundNodes:[SKNode] = []
var backgroundNodesSpeedFactor:[CGVector] = [] // in relation to camera nodes speed

func addParallaxBackgroundNode(background:SKNode, vector:CGVector) {
    backgroundNodes.append(background)
    backgroundNodesSpeedFactor.append(vector)
}

填充新变量的init（）也可能很有用

init(position:CGPoint) {
  super.init()
  self.position = position
}

现在我们可以填充didSet（）侦听器：

// Move our backgrounds
var i = 0
for node in backgroundNodes {

    let positionChangeX = position.x-oldValue.x
    let positionChangeY = position.y-oldValue.y
    let changeX = positionChangeX*backgroundNodesSpeedFactor[i].dx
    let changeY = positionChangeY*backgroundNodesSpeedFactor[i].dy
    node.position = CGPointMake(node.position.x+changeX,node.position.y+changeY)

    i += 1
}

最终代码如下：

class CameraNodeParallax:SKCameraNode{

    var backgroundNodes:[SKNode] = []
    var backgroundNodesSpeedFactor:[CGVector] = [] // in relation to camera nodes speed

    init(position:CGPoint) {
        super.init()
        self.position = position
    }

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

    override var position : CGPoint {
        didSet {

            // Move your parallax backgrounds
                var i = 0
                for node in backgroundNodes {

                    let positionChangeX = position.x-oldValue.x
                    let positionChangeY = position.y-oldValue.y
                    let changeX = positionChangeX*backgroundNodesSpeedFactor[i].dx
                    let changeY = positionChangeY*backgroundNodesSpeedFactor[i].dy
                    node.position = CGPointMake(node.position.x+changeX,node.position.y+changeY)

                    i += 1
                }
        }
    }

    func addParallaxBackgroundNode(background:SKNode, vector:CGVector) {
        backgroundNodes.append(background)
        backgroundNodesSpeedFactor.append(vector)
    }
}

我在这里创建了一个不从SKCameraNode继承的替代实现https://github.com/gitmalong/lovelySpriteKitHelpers/blob/master/ParallaxBackgroundMover.swift

Answer 2

我在iOS 9 SpriteKit游戏中使用了视差效果。

基本上你要在你的场景update()函数中添加几行代码，将方块移动到相机的相反方向，但是有一些缩放因子。

update(){
  let moveXFactor: CGFloat = 3
  let moveYFactor: CGFloat = 2
  camera.position = CGPoint( camera.position.x + moveXFactor, camera.position.y + moveYFactor )

  let redSquareParallaxSpeedFactor: CGFloat = -0.2
  let blueSquareParallaxSpeedFactor: CGFloat = -0.1
  redSquare.position = CGPoint( redSquare.position.x + redSquareParallaxSpeedFactor * moveXFactor, redSquare.position.y + redSquareParallaxSpeedFactor * moveYFactor )
  blueSquare.position = CGPoint( blueSquare.position.x + blueSquareParallaxSpeedFactor * moveXFactor, blueSquare.position.y + blueSquareParallaxSpeedFactor * moveYFactor )
}

这是一个简化的例子。使用一个跟踪fps的变量和一个时钟，并根据一个恒定的时间刻度移动对象，而不是根据设备的当前fps不断变慢或变慢的时间。

因此，在场景的类文件中定义一些变量。

var lastUpdate: NSTimeInterval
var deltaTime: CGFloat

然后在场景类的init()函数中初始化它们。

lastUpdate = 0
deltaTime = 0.01666

最后，在场景的update()功能中每次刷新时更新它们。

deltaTime = CGFloat( currentTime - lastUpdate )
lastUpdate = currentTime

if deltaTime > 1.0 {
  deltaTime = 0.0166
}

现在，这个时钟工作，让我们用它来缩放视差效果，让它更顺畅。

update(){
  deltaTime = CGFloat( currentTime - lastUpdate )
  lastUpdate = currentTime

  if deltaTime > 1.0 {
    deltaTime = 0.0166
  }

  let someScale: CGFloat = 0.001

  var moveXFactor: CGFloat = 3 * deltaTime * someScale
  var moveYFactor: CGFloat = 2 * deltaTime * someScale
  camera.position = CGPoint( camera.position.x + moveXFactor, camera.position.y + moveYFactor )

  let redSquareParallaxSpeedFactor: CGFloat = -0.2
  let blueSquareParallaxSpeedFactor: CGFloat = -0.1
  redSquare.position = CGPoint( redSquare.position.x + redSquareParallaxSpeedFactor * moveXFactor, redSquare.position.y + redSquareParallaxSpeedFactor * moveYFactor )
  blueSquare.position = CGPoint( blueSquare.position.x + blueSquareParallaxSpeedFactor * moveXFactor, blueSquare.position.y + blueSquareParallaxSpeedFactor * moveYFactor )
}

SpriteKit - SKCameraNode视差效果？

2 个答案: