I am trying to load a .sdf (Simulation Description Format) file and display it as a 3D model using Swift, UIKit, and SceneKit on iPad and macOS only. However, SceneKit does not directly support loading .sdf files.

I attempted to parse the .sdf file using an XML parser, but I wasn’t successful. I would prefer to load the .sdf file without converting it to another format, if possible. As I am new to Swift, I need guidance on how to achieve this

What I’ve tried:

Used an XML parser to try and parse the .sdf file.
Searched for any SceneKit extensions or libraries that might support .sdf files directly.
Environment:

Swift
UIKit
SceneKit

below is my codes

import UIKit
import SceneKit
import PhyKit

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        self.view.backgroundColor = .white
        
        // Load and display the SDF model
            if let sdfURL = Bundle.main.url(forResource: "model", withExtension: "sdf") {
                    loadAndDisplaySDFModel(from: sdfURL)
                }
        
            }
        
        
        func loadAndDisplaySDFModel(from url: URL) {
                // Create a new SceneKit scene
                let scene = SCNScene()
                
                // Parse the SDF file and add nodes to the scene
                if let sdfNodes = parseSDFFile(at: url) {
                    for node in sdfNodes {
                        scene.rootNode.addChildNode(node)
                    }
                }
                
                // Create a SceneKit view and set its scene
                let scnView = SCNView(frame: self.view.frame)
                scnView.scene = scene
                
                // Add the SceneKit view to the view controller's view
                self.view.addSubview(scnView)
                
                // Allow the user to manipulate the camera
                scnView.allowsCameraControl = true
            scnView.autoenablesDefaultLighting = true
            scnView.backgroundColor = .white
            }
        
        func parseSDFFile(at url: URL) -> [SCNNode]? {
                // Read the file content
                guard let data = try? Data(contentsOf: url) else {
                    print("Failed to read SDF file")
                    return nil
                }
                
                // Parse the XML
                let parser = XMLParser(data: data)
                let sdfParserDelegate = SDFParserDelegate()
                parser.delegate = sdfParserDelegate
                
                if parser.parse() {
                    
                    return sdfParserDelegate.nodes
                } else {
                    print("Failed to parse SDF file")
                    return nil
                }
            }
}

class SDFParserDelegate: NSObject, XMLParserDelegate {
    var nodes: [SCNNode] = []
    var currentElement: String = ""
    
    func parser(_ parser: XMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String] = [:]) {
        currentElement = elementName
        
        if elementName == "box" {
            let size = attributeDict["size"]?.split(separator: " ").map { CGFloat(Double($0) ?? 1.0) } ?? [1.0, 1.0, 1.0]
            let box = SCNBox(width: size[0], height: size[1], length: size[2], chamferRadius: 0.0)
            let material = SCNMaterial()
            material.diffuse.contents = UIColor.red
            box.materials = [material]
            let boxNode = SCNNode(geometry: box)
            nodes.append(boxNode)
        }
    }
    
    func parser(_ parser: XMLParser, foundCharacters string: String) {
        // Handle found characters if needed
    }
    
    func parser(_ parser: XMLParser, didEndElement elementName: String, namespaceURI: String?, qualifiedName qName: String?) {
        currentElement = ""
    }
}

Thank you for your help!