swift - 如何让 Sprite 跟随另一个 "within bounds"

Question

我想创建一个关注用户的眼球。从这个意义上讲，眼睛应该跟随用户的位置，但只能在一定范围内移动(眼窝)。我在下面编写的代码有效，但它非常不稳定。

if(dist <= socketRadius - self.aEye.size.width/2.2){
    lastPosition = self.aEye.position
    self.aEye.physicsBody?.velocity = CGVector(dx:theVec.dx * eyeMoveSpeed, dy:theVec.dy * eyeMoveSpeed)
}
else{

    let toCenterVector = normalizeVector( CGVector(dx:(self.socket.position.x - self.aEye.position.x), dy:(self.socket.position.y - self.aEye.position.y)*3 ))
    self.aEye.physicsBody?.velocity = toCenterVector
    print(toCenterVector)
    print("Out")
}

(dist是眼球到眼窝中心的距离)

有没有办法让眼球在眼窝周围顺畅流动以跟随用户的位置？

Answer 1

您可以使用 SKConstraints 来实现这一点。像这样的东西:

let rangeToCenterSprite = SKRange(lowerLimit: 80, upperLimit: 90)
var distanceConstraint: SKConstraint

distanceConstraint = SKConstraint.distance(rangeToCenterSprite, toNode: SpriteNodeInEyeCenter)
EyeBallSprite.constraints = [distanceConstraint]