ios - 在 Sprite Kit 中拖动一个对象与另一个对象碰撞时不会发生弹跳

Question

Here是我遇到的问题的视频。正如您在视频中看到的那样，我移动了一个灰色的球，试图与一个红色的球碰撞。当两个物体碰撞时没有弹跳发生，红球只是移动。我试过调整红球的密度，比如让红球的密度为 0.00001。碰撞行为没有差异。

如何更改碰撞行为以产生弹跳？

这是灰色球的属性:

func propertiesGrayBall() {
    gray = SKShapeNode(circleOfRadius: frame.width / 10 )
    gray.physicsBody = SKPhysicsBody(circleOfRadius: frame.width / 10 )
    gray.physicsBody?.affectedByGravity = false
    gray.physicsBody?.dynamic = true
    gray.physicsBody?.allowsRotation = false
    gray.physicsBody?.restitution = 1
}

这是红球的属性:

func propertiesRedBall  {
    let redBall = SKShapeNode(circleOfRadius: self.size.width / 20
    redBall.physicsBody = SKPhysicsBody(self.size.width / 20)
    redBall.physicsBody?.affectedByGravity = false
    redBall.physicsBody?.dynamic = true
    redBall.physicsBody?.density = redBall.physicsBody!.density * 0.000001
    redBall.physicsBody?.allowsRotation = false
    redBall.physicsBody?.restitution = 1
}

下面是我如何移动灰色球。

override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
    if fingerIsOnGrayBall {
        let touch = touches.first
        var position = touch!.locationInView(self.view)
        position = self.convertPointFromView(position)
        grayBall.position = position
    }
}

主要修改球原本有附件。我删除了它们以简化问题。这就是注释可能与代码不一致的原因。

Answer 1

如果您通过直接或使用 SKAction 设置其位置来移动节点(带有物理体)，则该节点将不会成为物理模拟的一部分。相反，您应该通过施加力/脉冲或设置其速度来移动节点。以下是如何执行此操作的示例:

首先，定义一个变量来存储触摸的位置

class GameScene: SKScene {
    var point:CGPoint?

然后，从您的代码中删除以下语句

redBall.physicsBody?.density = redBall.physicsBody!.density * 0.000001

最后，添加以下触摸处理程序

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    /* Called when a touch begins */

    for touch in touches {
        let location = touch.locationInNode(self)

        let node = nodeAtPoint(location)
        if (node.name == "RedBall") {
            point = location
        }
    }
}

override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
   /* Called when a touch begins */

    for touch in touches {
        let location = touch.locationInNode(self)
        if point != nil {
            point = location
        }
    }
}

override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
    point = nil
}

override func update(currentTime: CFTimeInterval) {
    if let location = point {
        let dx = location.x - redBall.position.x
        let dy = location.y - redBall.position.y
        let vector = CGVector(dx: dx*100, dy: dy*100)
        redBall.physicsBody?.velocity = vector
    }
}