重力場不起作用，物體浮在真空中

我試圖在一個飛機上有5個球的世界中模擬重力。我遇到的第一個問題是，球穿過地板是因爲它們具有動態的身體。但是如果我使用運動機構，他們不會受到力量的影響。所以我不得不使用一個動態的物體，禁用重力並改用重力場。場景從COLLADA文件加載。這就是我設置的東西：重力場不起作用，物體浮在真空中

self.scene = SCNScene(named: "art.scnassets/Balls.dae")! 

for i in 1...5 { 
    let sphere = scene.rootNode.childNode(withName: "Sphere\(i)", recursively: true)! 
    let shape = SCNPhysicsShape(geometry: sphere.geometry!, options: nil) 
    let body = SCNPhysicsBody(type: .dynamic, shape: shape) 
    body.mass = 0.2 
    body.isAffectedByGravity = false 
    body.categoryBitMask = BallCategory 
    body.collisionBitMask = PlaneCategory | BallCategory | GravityFieldCategory 
    sphere.physicsBody = body 

    balls.append(sphere) 
} 

self.plane = self.scene.rootNode.childNode(withName: "Plane", recursively: true) 
let shape = SCNPhysicsShape(geometry: self.plane.geometry!, options: nil) 
let body = SCNPhysicsBody(type: .static, shape: shape) 
body.categoryBitMask = PlaneCategory 
body.collisionBitMask = BallCategory 
self.plane.physicsBody = body 

// Create a gravity field 
let gravityField = SCNPhysicsField.linearGravity() 
gravityField.categoryBitMask = GravityFieldCategory 
gravityField.direction = SCNVector3Make(0.0, -1.0, 0.0) 
gravityField.isActive = true 
gravityField.strength = 3.0 
let gravityNode = SCNNode() 
gravityNode.physicsField = gravityField 
self.scene.rootNode.addChildNode(gravityNode)

然後，當用戶觸摸屏幕時，隨機球向上移動，它應該跌下來：

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { 
    let index = Int(arc4random_uniform(5)) 
    let ball = self.ball(atIndex: index) 

    let moveUp = SCNAction.move(by: SCNVector3Make(0.0, 2.0, 0.0), duration: 1.5) 
    ball.runAction(moveUp) 
}

但不降下來，它只是停在那裏，漂浮在真空中。重力場不起作用。這是發生了什麼事情：https://youtu.be/egMe4lgPZY0

來源

2016-09-25 Ramy Al Zuhouri

看起來飛機的形狀是不正確的。我試圖只是路過零爲外形的參數來創建平面的物理體：


    self.plane = self.scene.rootNode.childNode(withName: "Plane", recursively: true) 
     let shape = SCNPhysicsShape(geometry: self.plane.geometry!, options: nil) 
    let body = SCNPhysicsBody(type: .static, shape:nil) 
    body.categoryBitMask = PlaneCategory 
    body.collisionBitMask = BallCategory 
    self.plane.physicsBody = body

而且我刪除了重力場並打開球的 isAffectedbyGravity財產。它現在有效。

來源

2016-09-25 20:39:15

重力場不起作用，物體浮在真空中

回答

相關問題