Sk Physics Joint工作不正常

Question

我正在创造一个游戏，对于我的角色，他的腿和躯干有不同的动画，因此它们是具有单独物理体的独立节点。我在连接躯干和腿部时遇到了很多麻烦，然而，连接它们不是问题，保持联系是。在移动的同时，英雄的躯干有时从腿上滑落。有点搞笑但不实用哈哈。这是我的物理编码

enum BodyType:UInt32 {

case bullet1 = 2

case enemy1 =  4
case enemy2 =  16
case enemy3 =  32

case desertForegroundCase = 64

case tank11 =  128
case tank12 =  256
case tank13 =  512

case tank21 =  1024
case tank22 =  2048
case tank23 =  4056

case tank31 =  8112
case tank32 =  16224
case tank33 =  32448

case cliff1 =  64856
case cliff2 =  129212

case soldierT = 258424
case soldierL = 516848

}

 func CreateScene (){

desertBackground.position = CGPoint(x: frame.size.width / 2, y: 
frame.size.height / 2)
desertBackground.size = CGSize (width: 1136, height: 640)
desertBackground.zPosition = -5
desertForegroundImage.position = CGPointMake(568, 100)
desertForegroundImage.zPosition = -1
let desertForeground = SKSpriteNode(texture: 
desertForegroundTexture, size:CGSize(width: 1136, height: 200))
    desertForeground.position = CGPointMake(568, 100)
let desertForegroundBody = SKPhysicsBody(texture: 
desertForegroundTexture, size: CGSize(width: 1136, height: 200))
desertForegroundBody.dynamic = false
desertForegroundBody.affectedByGravity = false
desertForegroundBody.allowsRotation = false
desertForegroundBody.categoryBitMask = 
BodyType.deserForegroundcase.rawValue
desertForegroundBody.contactTestBitMask = BodyType.enemy1.rawValue 
| BodyType.enemy2.rawValue | BodyType.enemy3.rawValue  | 
BodyType.soldierL.rawValue | BodyType.soldierT.rawValue
desertForeground.physicsBody = desertForegroundBody
desertForeground.zPosition = -1

self.addChild(desertForegroundImage)
self.addChild(desertForeground)
self.addChild(desert gully)

}
func CreateHero (){

soldierLegs.position = CGPoint(x: 405 , y: 139)
soldierLegs.zPosition = 1
soldierLegs.anchorPoint.x = 0.6
soldierLegs.anchorPoint.y = 0.7

let soldierLegsBody:SKPhysicsBody = SKPhysicsBody(rectangleOfSize: 
soldierLegs.size)
soldierLegsBody.dynamic = true
soldierLegsBody.affectedByGravity = true
soldierLegsBody.allowsRotation = false
//body.restitution = 0.4
soldierLegsBody.categoryBitMask = BodyType.soldierL.rawValue
soldierLegsBody.contactTestBitMask = BodyType.enemy1.rawValue | 
BodyType.enemy2.rawValue | BodyType.enemy3.rawValue  | 
BodyType.desertForegroundCase.rawValue
soldierLegs.physicsBody = soldierLegsBody

soldierTorso.position = soldierLegs.position
soldierTorso.zPosition = 2
soldierTorso.anchorPoint.x = 0.25
soldierTorso.anchorPoint.y = 0.1

let soldierTorsoBody:SKPhysicsBody = SKPhysicsBody(rectangleOfSize: 
soldierTorso.size)
soldierTorsoBody.dynamic = true
soldierTorsoBody.affectedByGravity = true
soldierTorsoBody.allowsRotation = false
soldierTorsoBody.categoryBitMask = BodyType.soldierT.rawValue
soldierTorsoBody.contactTestBitMask = BodyType.enemy1.rawValue | 
BodyType.enemy2.rawValue | BodyType.enemy3.rawValue  | 
BodyType.desertForegroundCase.rawValue
soldierTorso.physicsBody = soldierTorsoBody
let joint  = 
SKPhysicsJointFixed.jointWithBodyA(soldierLegs.physicsBody!, bodyB: 
soldierTorso.physicsBody!, anchor: soldierLegs.position)

self.addChild(soldierTorso)
self.addChild(soldierLegs)
self.physicsWorld.addJoint(joint)
}

这是关于他会走多远的距离。有没有办法只用一个具有2个独立节点的物理体编码？或者我只是错过了一些小代码？任何帮助都有帮助，谢谢。