Instantiating class doesnt work - swift - ios

Question

I have a simple function call in my main class to create some instances from my Cube class but I cant seem to get my instances to be added to my scene. I tried returning self inside my Cube class but Swift wont let me do this inside init.
func addCubeLoop() {
for var i = 0; i <= 0; ++i {
cube = Cube(num: i, importedCube: importedCube1)
cubeArray.append(cube)
theScene.rootNode.addChildNode(cubeArray[i])
}
}
class Cube: SCNNode {
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
init(num: Int, importedCube: SCNNode) {
let _scale: Float = 60
let cube: SCNNode = importedCube.copy() as! SCNNode
super.init()
cube.scale = SCNVector3Make(_scale, _scale, _scale)
let node = SCNNode()
node.addChildNode(cube)
node.position = SCNVector3Make(5, 20, 3)
let collisionBox = SCNBox(width: 5.0, height: 5.0, length: 5.0, chamferRadius: 0)
node.physicsBody?.physicsShape = SCNPhysicsShape(geometry: collisionBox, options: nil)
node.physicsBody = SCNPhysicsBody.dynamicBody()
node.physicsBody?.mass = 0.1
node.physicsBody?.restitution = 0.8
node.physicsBody?.damping = 0.5
node.name = "dice" + String(num)
node.physicsBody?.allowsResting = true
}
}

Answer 1

The nodes created in the init of Cube are not added as child nodes of it.
I've simplified the your code below to illustrate the problem.
func addCubeLoop() {
for /* loop */ {
// 1. create cube
cube = Cube(num: i, importedCube: importedCube1)
// 6. add cube to the scene's root node
theScene.rootNode.addChildNode(cubeArray[i])
}
}
class Cube: SCNNode {
init(importedCube: SCNNode) {
// 2. copy importedCube
let cube: SCNNode = importedCube.copy() as! SCNNode
// configure cube
// ...
// 3. create node
let node = SCNNode()
// 4. add cube (the copy) to node
node.addChildNode(cube)
// configure node
// ...
// 5. End of init
}
}
For each run through the loop, this is what happens.
A new Cube instance is created, passing importedCube1
In the Cube initializer, the imported cube argument is copied. The node "cube" is now a copy of the argument.
Still in the initializer, a new node (called "node" is created).
Still in the initializer, "cube" (the copy) is added to "node". At this point, cube is a child node of "node", but the Cube instance itself (which is a node) had no child nodes.
Init completes.
The newly created Cube instance is added to the scene's root node.
At this point there are four relevant nodes:
the root node,
the cube instance node
the node called "node"
the imported copy
The cube instance node is a child of the root node. The imported copy is a child of the "node" node. However, The "node" node doesn't have a parent.
The fix is to make sure that the all nodes are part of the hierarchy by adding the "node" node to self inside the Cube instance initializer.