Loading an .obj file with Expo-three? - react-native

Question

I am trying to insert a .obj file into a React Native app built using Expo.
From the examples I've found that are successfully working, most of these seem to rely on building spheres or cubes within the rendering. I haven't found a good example with a successful rendering of a local file, specifically .obj.
I'm using the expo-three documentation which describes rendering with obj files, but no working examples.
This is what I have so far, which is not producing any rendered object. But want to know if I am on the right track with this, and what I am missing to get the object to render.
Below is the current file code.
import { Renderer, TextureLoader } from 'expo-three';
import * as React from 'react';
import { OBJLoader } from 'three/examples/jsm/loaders/OBJLoader';
import {
AmbientLight,
Fog,
GridHelper,
PerspectiveCamera,
PointLight,
Scene,
SpotLight,
} from 'three';
import { Asset } from 'expo-asset';
import { MTLLoader } from 'three/examples/jsm/loaders/MTLLoader';
export default function ThreeDPhytosaur() {
return (
<GLView
style={{ flex: 1 }}
onContextCreate={async (gl) => {
const { drawingBufferWidth: width, drawingBufferHeight: height } = gl;
const sceneColor = 0x6ad6f0;
const renderer = new Renderer({ gl });
renderer.setSize(width, height);
renderer.setClearColor(sceneColor);
const camera = new PerspectiveCamera(70, width / height, 0.01, 1000);
camera.position.set(2, 5, 5);
const scene = new Scene();
scene.fog = new Fog(sceneColor, 1, 10000);
scene.add(new GridHelper(10, 10));
const ambientLight = new AmbientLight(0x101010);
scene.add(ambientLight);
const pointLight = new PointLight(0xffffff, 2, 1000, 1);
pointLight.position.set(0, 200, 200);
scene.add(pointLight);
const spotLight = new SpotLight(0xffffff, 0.5);
spotLight.position.set(0, 500, 100);
spotLight.lookAt(scene.position);
scene.add(spotLight);
const asset = Asset.fromModule(model['phytosaur']);
await asset.downloadAsync();
const objectLoader = new OBJLoader();
const object = await objectLoader.loadAsync(asset.uri);
object.scale.set(0.025, 0.025, 0.025);
scene.add(object);
camera.lookAt(object.position);
const render = () => {
timeout = requestAnimationFrame(render);
renderer.render(scene, camera);
gl.endFrameEXP();
};
render();
}}
/>
);
}
const model = {
'phytosaur': require('../assets/phytosaur.obj'),
};
Thanks very much!

Answer 1

This is the code that I got to render the obj file. Changed the structure of the original file based on some other examples found.
But this might help someone else!
import { OBJLoader } from 'three/examples/jsm/loaders/OBJLoader.js';
import { Asset } from 'expo-asset';
import { Renderer} from 'expo-three';
import * as React from 'react';
import {
AmbientLight,
Fog,
PerspectiveCamera,
PointLight,
Scene,
SpotLight,
} from 'three';
export default function ThreeDTwo() {
let timeout;
React.useEffect(() => {
// Clear the animation loop when the component unmounts
return () => clearTimeout(timeout);
}, []);
return (
<GLView
style={{ flex: 1 }}
onContextCreate={async (gl) => {
const { drawingBufferWidth: width, drawingBufferHeight: height } = gl;
const sceneColor = 668096;
// Create a WebGLRenderer without a DOM element
const renderer = new Renderer({ gl });
renderer.setSize(width, height);
renderer.setClearColor(0x668096);
const camera = new PerspectiveCamera(70, width / height, 0.01, 1000);
camera.position.set(2, 5, 5);
const scene = new Scene();
scene.fog = new Fog(sceneColor, 1, 10000);
const ambientLight = new AmbientLight(0x101010);
scene.add(ambientLight);
const pointLight = new PointLight(0xffffff, 2, 1000, 1);
pointLight.position.set(0, 200, 200);
scene.add(pointLight);
const spotLight = new SpotLight(0xffffff, 0.5);
spotLight.position.set(0, 500, 100);
spotLight.lookAt(scene.position);
scene.add(spotLight);
const asset = Asset.fromModule(require("../assets/phytosaur_without_mtl.obj"));
await asset.downloadAsync();
// instantiate a loader
const loader = new OBJLoader();
// load a resource
loader.load(
// resource URL
asset.localUri,
// called when resource is loaded
function ( object ) {
object.scale.set(0.065, 0.065, 0.065)
scene.add( object );
camera.lookAt(object.position)
//rotate my obj file
function rotateObject(object, degreeX=0, degreeY=0, degreeZ=0) {
object.rotateX(THREE.Math.degToRad(degreeX));
object.rotateY(THREE.Math.degToRad(degreeY));
object.rotateZ(THREE.Math.degToRad(degreeZ));
}
// usage:
rotateObject(object, 0, 0, 70);
//animate rotation
function update() {
object.rotation.x += 0.015
}
const render = () => {
timeout = requestAnimationFrame(render);
update();
renderer.render(scene, camera);
gl.endFrameEXP();
};
render();
},
// called when loading is in progresses
function ( xhr ) {
console.log( ( xhr.loaded / xhr.total * 100 ) + '% loaded' );
},
// called when loading has errors
function ( error ) {
console.log( error );
}
);
}}
/>
);
}