AR Portal Scene created with NSSBoxes.

ViewController.swift

func setupScene() {
        let node = SCNNode()
        node.position = SCNVector3.init(0, 0, 0)

        let leftWall = createBox(isDoor: false)
        leftWall.position = SCNVector3.init((-length / 2) + width, 0, 0)
        leftWall.eulerAngles = SCNVector3.init(0, 180.0.degreesToRadians, 0)
        
        let rightWall = createBox(isDoor: false)
        rightWall.position = SCNVector3.init((length / 2) - width, 0, 0)
        
        let topWall = createBox(isDoor: false)
        topWall.position = SCNVector3.init(0, (height / 2) - width, 0)
        topWall.eulerAngles = SCNVector3.init(0, 0, 90.0.degreesToRadians)
        
        let bottomWall = createBox(isDoor: false)
        bottomWall.position = SCNVector3.init(0, (-height / 2) + width, 0)
        bottomWall.eulerAngles = SCNVector3.init(0, 0, -90.0.degreesToRadians)
        
        let backWall = createBox(isDoor: false)
        backWall.position = SCNVector3.init(0, 0, (-length / 2) + width)
        backWall.eulerAngles = SCNVector3.init(0, 90.0.degreesToRadians, 0)
        
        let leftDoorSide = createBox(isDoor: true)
        leftDoorSide.position = SCNVector3.init((-length / 2 + width) + (doorLength / 2), 0, (length / 2) - width)
        leftDoorSide.eulerAngles = SCNVector3.init(0, -90.0.degreesToRadians, 0)
        
        let rightDoorSide = createBox(isDoor: true)
        rightDoorSide.position = SCNVector3.init((length / 2 - width) - (doorLength / 2), 0, (length / 2) - width)
        rightDoorSide.eulerAngles = SCNVector3.init(0, -90.0.degreesToRadians, 0)
        
        
        //Adding Nodes to Main Node
        node.addChildNode(leftWall)
        node.addChildNode(rightWall)
        node.addChildNode(topWall)
        node.addChildNode(bottomWall)
        node.addChildNode(backWall)
        node.addChildNode(leftDoorSide)
        node.addChildNode(rightDoorSide)
        
        self.sceneView.scene.rootNode.addChildNode(node)
    }