Model I/O importing assets

Question

I'm trying to use Model I/O as a quicker way to render imported 3d models for my iOS app. I have written a little bit of code importing and displaying a 3d model I have made with a .obj file format. For some reason, when I run my app only a black screen appears.Here is my code:

import UIKit
import ModelIO
import SceneKit
import SceneKit.ModelIO

class ViewController: UIViewController {


var sceneView: SCNView {
    return self.view as! SCNView
}

override func viewDidLoad() {
     // Do any additional setup after loading the view, typically from                a nib.
    guard let url = Bundle.main.url(forResource: "Digestive_System",      withExtension: "obj") else {
        fatalError("Failed to find model")

    }

    //Load Object
    let asset = MDLAsset(url:url)
    guard let object = asset.object(at: 0) as? MDLMesh else {
        fatalError("failed to get mesh from asset")
    }

    // Wrap Model I/O object in SceneKit object
    let scene = SCNScene()
    let node = SCNNode(mdlObject: object)
    scene.rootNode.addChildNode(node)


    //Display Scene

    sceneView.autoenablesDefaultLighting = true
    sceneView.allowsCameraControl = true
    sceneView.scene = scene
    sceneView.backgroundColor = UIColor.black








     super.viewDidLoad()
     }

side note: my model is located in the main folder of the app.

Thanks for your help guys! Noa

score 0 · Answer 1 · answered Apr 03 '19 at 10:06

I have rendered .Obj model using Model I/O as:

Load model from bundle

NSURL *url = [[NSBundle mainBundle] URLForResource:@"modelName" withExtension:@"obj"];
MDLAsset *asset = [[MDLAsset alloc] initWithURL:url];
MDLMesh *meshObject = (MDLMesh *)[asset objectAtIndex:0];

Apply material to model

MDLScatteringFunction *scattering = [MDLScatteringFunction new];
MDLMaterial *mdMaterial = [[MDLMaterial alloc] initWithName:@"material" 
scatteringFunction:scattering];

NSURL *baseMaterialURL = [[NSBundle mainBundle] 
URLForResource:@"Image_Base_Color" withExtension:@"png"];
MDLMaterialProperty *baseColor = [MDLMaterialProperty new];
[baseColor setType:MDLMaterialPropertyTypeTexture];
[baseColor setSemantic:MDLMaterialSemanticBaseColor];
[baseColour setURLValue:baseMaterialURL];
[material setProperty:baseColor];

 for(MDLSubmesh *subMesh in meshObject.submeshes)
 {
    sub.material = material;
 }

Add model to scene

 SCNNode *baseModelNode = [SCNNode nodeWithMDLObject:object];
 [self.sceneView.scene rootNode] addChildNode:self.baseModelNode];

You can set scale and position as per your requirement.

Model I/O importing assets

1 Answers1