gistfile1.txt

/*
See LICENSE folder for this sample’s licensing information.

Abstract:
Wrapper SceneKit node for virtual objects placed into the AR scene.
*/

import Foundation
import SceneKit
import ARKit

class VirtualObject: SCNNode {
    
    var modelName: String = ""
    var fileExtension: String = ""
    var thumbImage: UIImage!
    var title: String = ""
    var modelLoaded: Bool = false
    
    var viewController: ViewController?
    
    override init() {
        super.init()
        self.name = "Virtual object root node"
    }
    
    init(geometry: SCNGeometry?) {
        super.init()
        self.geometry = geometry
        self.name = "Virtual object root node"
        self.modelName = "modelName"
        self.fileExtension = "fileExtension"
        self.thumbImage = #imageLiteral(resourceName: "tom")
        self.title = "Tom"
        
    }
    
    init(modelName: String, fileExtension: String, thumbImageFilename: String, title: String) {
        super.init()
        
        self.name = "Virtual object root node"
        self.modelName = modelName
        self.fileExtension = fileExtension
        self.thumbImage = UIImage(named: thumbImageFilename)
        self.title = title
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    func loadModel() {
        guard let virtualObjectScene = SCNScene(named: "\(modelName).\(fileExtension)", inDirectory: "Models.scnassets/\(modelName)") else {
            return
        }
        
        let wrapperNode = SCNNode()
        
        for child in virtualObjectScene.rootNode.childNodes {
            child.geometry?.firstMaterial?.lightingModel = .physicallyBased
            child.movabilityHint = .movable
            wrapperNode.addChildNode(child)
        }
        self.addChildNode(wrapperNode)
        
        modelLoaded = true
    }
    
    func unloadModel() {
        for child in self.childNodes {
            child.removeFromParentNode()
        }
        
        modelLoaded = false
    }
    
    func translateBasedOnScreenPos(_ pos: CGPoint, instantly: Bool, infinitePlane: Bool) {
        
        guard let controller = viewController else {
            return
        }
        
        let result = controller.worldPositionFromScreenPosition(pos, objectPos: self.position, infinitePlane: infinitePlane)

        controller.moveVirtualObjectToPosition(result.position, instantly, !result.hitAPlane)
    }
}

extension VirtualObject {
    
    static func isNodePartOfVirtualObject(_ node: SCNNode) -> Bool {
        if node.name == "Virtual object root node" {
            return true
        }
        
        if node.parent != nil {
            return isNodePartOfVirtualObject(node.parent!)
        }
        
        return false
    }
}

// MARK: - Protocols for Virtual Objects

protocol ReactsToScale {
    func reactToScale()
}

extension SCNNode {
    
    func reactsToScale() -> ReactsToScale? {
        if let canReact = self as? ReactsToScale {
            return canReact
        }
        
        if parent != nil {
            return parent!.reactsToScale()
        }
        
        return nil
    }
}