SKRode zRotation value using pinned = true and allows Rotation = false

Question

SKRode zRotation value using pinned = true and allows Rotation = false

This issue is probably related to this issue . However, I do not have enough reputation to add to this discussion.

When the zRotation of the pinned symbol node reaches (or possibly becomes close) a positive or negative PI in the scene space and node.physicsBody.allowRotation = false, the node local zRotation instantly goes negative or positive 5,497 ... radians, depending on the direction of rotation .

If the nodes are moving, the visual result is a chain of nodes that rotate around, tremble and / or are generally erroneous.

If the nodes do not move, the results still occur, but without a noticeable visual effect.

I recreated the problem in a small test case below.

Edit: This problem seems to be limited to where the bodies are fixed in series. I saw both here, where the nodes are nested, and where the nodes have the same parent and are manually pinned to the series.

Edit 2: Changed test case for outputting node zRotation values during update sequence.

Edit 3: Confirmed with Apple, this is a bug.

import SpriteKit class GameScene: SKScene { var nodes :[SKNode] required init?(coder aDecoder: NSCoder) { nodes = Array<SKNode>() super.init(coder: aDecoder) } override func didMoveToView(view: SKView) { NSLog("Create nodes") physicsWorld.speed = 0.5 var prev = self as SKNode var newNode:SKShapeNode for n in 0...5{ newNode = SKShapeNode(circleOfRadius: 20) newNode.name = String(n) newNode.position = (n==0 ? CGPoint(x: 400, y: 400):CGPoint(x: 50, y: 0)) newNode.zRotation = CGFloat(M_PI/4) prev.addChild(newNode) prev = newNode newNode.physicsBody = SKPhysicsBody(circleOfRadius: 20, center: CGPoint(x: 0, y: 0)) newNode.physicsBody?.affectedByGravity = true newNode.physicsBody?.dynamic = (n==0 ? false : true) newNode.physicsBody?.pinned = true newNode.physicsBody?.affectedByGravity = false newNode.physicsBody?.allowsRotation = (n==1 ? true : false) // allowing rotation removes issue newNode.physicsBody?.collisionBitMask = 0x00000000 nodes.append(newNode) NSLog("node \(newNode.name):\(newNode.zRotation)") } } override func update(currentTime: NSTimeInterval) { NSLog("update") for node in nodes{ NSLog("node \(node.name):\(node.zRotation)") } } override func didEvaluateActions() { NSLog("didEvaluateActions") for node in nodes{ NSLog("node \(node.name):\(node.zRotation)") } } override func didSimulatePhysics() { NSLog("didSimulatePhysics") for node in nodes{ NSLog("node \(node.name):\(node.zRotation)") } } override func didApplyConstraints() { NSLog("didApplyConstraints") for node in nodes{ NSLog("node \(node.name):\(node.zRotation)") } } }

Output:

 Create nodes node Optional("0"):0.785398185253143 node Optional("1"):0.785398185253143 node Optional("2"):0.785398185253143 node Optional("3"):0.785398185253143 node Optional("4"):0.785398185253143 node Optional("5"):0.785398185253143 update node Optional("0"):0.785398185253143 node Optional("1"):0.785398185253143 node Optional("2"):0.785398185253143 node Optional("3"):0.785398185253143 node Optional("4"):0.785398185253143 node Optional("5"):0.785398185253143 didEvaluateActions node Optional("0"):0.785398185253143 node Optional("1"):0.785398185253143 node Optional("2"):0.785398185253143 node Optional("3"):0.785398185253143 node Optional("4"):0.785398185253143 node Optional("5"):0.785398185253143 didSimulatePhysics node Optional("0"):0.785398185253143 node Optional("1"):0.785398185253143 node Optional("2"):0.785398185253143 node Optional("3"):-5.49778699874878 <<<<< node Optional("4"):0.785398006439209 node Optional("5"):0.785398006439209