我正在使用 swift 和 sprite 套件开发一个 Xcode 项目,我想知道如何选择哪些对象受径向重力场的影响。我目前有两颗恒星和一些行星,每颗恒星后面都有一个径向重力场。问题是恒星会被它们自己的引力场吸引。我怎样才能使每个重力场只影响一颗恒星和所有行星,而不影响它跟随的恒星。我知道它与 categoryBitMask 和/或 fieldBitMask 有关系,但我不知 Prop 体是怎么回事。提前致谢。下面是恒星和重力场的代码。我不希望重力场影响那颗恒星。
class star: SKSpriteNode {
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
init(imageNamed: String){
let imageTexture = SKTexture(imageNamed: imageNamed)
super.init(texture: imageTexture, color: nil, size: imageTexture.size())
let radius = self.size.width / 2
self.physicsBody = SKPhysicsBody(circleOfRadius: radius )
physicsBody?.dynamic = false
}
}
let star1 = star(imageNamed: "star")
let gravityField1 = SKFieldNode.radialGravityField()
star1.position = CGPoint(x: self.size.width / 4, y: self.size.height / 2)
star1.physicsBody?.friction = 0
star1.physicsBody?.linearDamping = 0
star1.physicsBody?.angularDamping = 0
star1.physicsBody?.angularVelocity = 0.2
star1.zPosition = 1
star1.name = "star"
addChild(star1)
gravityField1.enabled = true;
gravityField1.position = CGPoint(x: self.size.width / 4, y: self.size.height / 2)
gravityField1.strength = Float(pow(radius1, 2)) * pow(10, -3)
addChild(gravityField1)
最佳答案
下面是如何设置类别和字段位掩码的示例:
设置重力场的类别位掩码
gravityField1.categoryBitMask = gravityField1Category
gravityField2.categoryBitMask = gravityField2Category
设置位掩码,使每颗恒星都受到其他恒星重力场的影响,但不受其自身的影响
star1.physicsBody?.fieldBitMask = gravityField2Category
star2.physicsBody?.fieldBitMask = gravityField1Category
设置位掩码,使行星受到两个重力场的影响
planet.physicsBody?.fieldBitMask = gravityField1Category | gravityField2Category
关于swift - 选择哪些物体径向重力场会影响 swift,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/27390010/