Load a USDZ, OBJ, STL, or PLY into a SCNNode using ModelIO

loadFile.m

#import <SceneKit/ModelIO.h>

- (SCNNode *) loadFileIntoSCNNode:(NSString *)path {
  // Get the path as a file url
  NSURL *url = [NSURL fileURLWithPath:path];
  // Load the file using Model IO.
  // OBJ, STL, PLY, and USDZ are supported. Although binary PLY is not, so watch out.
  MDLAsset *asset = [[MDLAsset alloc] initWithURL:url];
  // Load the textures, not sure this is needed but what the heck!
  [asset loadTextures];

  // Make a new node for us to put everything in
  SCNNode *node = [SCNNode node];
  // Add all the objects from the MDLAsset
  for (int i = 0; i < asset.count; i++) {
    MDLObject* child = [asset objectAtIndex:i];
    // As a child node to our node
    [node addChildNode:[SCNNode nodeWithMDLObject:child]];
  }
  // Return the node
  return node;
}