How to join multiple nodes to one node in iOS scene - ios

Question

As we can see in below pic there all multiple nodes in the scene graph. The requirement is I want to add these nodes in one node as shown in image2. So In scene graph, I will have one node(chair) which will contain multiple nodes
Image1
Image2

Answer 1

You create a parent node and then add all your nodes as children.
i.e.:
var nodes: [SCNNode] = getMyNodes()
var parentNode = SCNNode()
parentNode.name = "chair"
for node in nodes {
parentNode.addChildNodes(node)
}
When you apply an update to a node, the update is also pushed down to the children, for example:
parentNode.transform = SCNMatrix4MakeTranslation(0, 0.5, 1.2)
will apply the same translation transformation to all the children attached to parentNode.
You can access a specific child using:
parentNode.childNode(withName: nameOfChildNode, recursively: true)
and get the parent of any child using:
myChildNode.parent
EDIT:
If you are importing from a scene file, you can still easily access your nodes programmatically:
let scene = SCNScene(named: "myScene.scn")
func getMyNodes() -> [SCNNode] {
var nodes: [SCNNode] = [SCNNode]()
for node in scene.rootNode.childNodes {
nodes.append(node)
}
return nodes
}
which, incidentally, means that you can ignore most of the above and use myScene.rootNode as the parent node.

Answer 2

My suggestions would be :
Statically : Create a new .scn file in which you drag & drop every node you're trying to group
Dynamically : Create a new SCNNode. For each node you're trying to group, use the .addChildNode method
I used the second one a couple of times to build dynamical scenes using ARKit. Worked like a charm.
Basically, I added all the childs of my .dae file to a SCNNode :
var node = SCNNode()
let scene = SCNScene(named: "myScene.dae")
var nodeArray = scene.rootNode.childNodes
for childNode in nodeArray {
node.addChildNode(childNode as SCNNode)
}
You should give it a try with your files, using the same .addChildNode method :)

Answer 3

in case, if somebody is looking for a solution like this yellow-black stick
class VirtualObject: SCNNode {
enum Style {
case anchor
case fence
}
let style: Style
var value: String?
init(_ style: Style) {
self.style = style
super.init()
switch style {
case .anchor:
let material = SCNMaterial()
material.diffuse.contents = UIColor.magenta
material.lightingModel = .physicallyBased
let object = SCNCone(topRadius: 0.02, bottomRadius: 0, height: 0.1) // SCNSphere(radius: 0.02)
object.materials = [material]
self.geometry = object
case .fence:
for index in 0 ... 6 {
let material = SCNMaterial()
material.diffuse.contents = index % 2 == 0 ? UIColor.yellow : UIColor.black
material.lightingModel = .physicallyBased
let node = SCNNode(geometry: SCNCylinder(radius: 0.01, height: 0.05))
node.geometry?.materials = [material]
node.transform = SCNMatrix4MakeTranslation(0, 0.05 * Float(index), 0)
addChildNode(node)
}
}
}