unable to load .mtl and .obj through react-three-renderer

Question

I'm trying to load .obj and .mtl through react-three-renderer but i'm missing out on loading the model. Currently i'm able to render a cube inside the div. However, i want to replace the cube with my .obj model.

installation:

npm install --save [email protected] [email protected] [email protected]
npm install --save react-three-renderer
npm install --save three-obj-loader
npm install --save three-mtl-loader

usage: cube inside a div

import React from 'react';
import React3 from 'react-three-renderer';
import * as THREE from 'three';
import OBJLoader from 'three-obj-loader';// added while importing character .obj
import OBJLoader from 'three-mtl-loader';// added while importing character .mtl


class Simple extends React.Component {
  static propTypes = {
    width: React.PropTypes.number.isRequired,
    height: React.PropTypes.number.isRequired,
  };

  constructor(props, context) {
    super(props, context);

    this.cameraPosition = new THREE.Vector3(0, 0, 5);

    // construct the position vector here, because if we use 'new' within render,
    // React will think that things have changed when they have not.

    this.state = {
      cubeRotation: new THREE.Euler(),
    };

    this._onAnimate = () => {
      // we will get this callback every frame

      // pretend cubeRotation is immutable.
      // this helps with updates and pure rendering.
      // React will be sure that the rotation has now updated.
      this.setState({
        cubeRotation: new THREE.Euler(
          this.state.cubeRotation.x + 0.1,
          this.state.cubeRotation.y + 0.1,
          0
        ),
      });
    };
  }

  render() {
    const {
      width,
      height,
    } = this.props;

    // or you can use:
    // width = window.innerWidth
    // height = window.innerHeight

    return (<React3
      mainCamera="camera" // this points to the perspectiveCamera below
      width={width}
      height={height}

      onAnimate={this._onAnimate}
    >
      <scene>
        <perspectiveCamera
          name="camera"
          fov={75}
          aspect={width / height}
          near={0.1}
          far={1000}

          position={this.cameraPosition}
        />
        <mesh
          rotation={this.state.cubeRotation}
        >
          <boxGeometry
            width={1}
            height={1}
            depth={1}
          />
          <meshBasicMaterial
            color={0x00ff00}
          />
        </mesh>
      </scene>
    </React3>);
  }
}

export default Simple;

Expected 3D model .obj .mtl but where to add this code ?

const mtlLoader = new THREE.MTLLoader();
mtlLoader.setBaseUrl(PATH);
mtlLoader.setPath(PATH); // One of these might not be needed
mtlLoader.crossOrigin = '*'; // Use as needed
mtlLoader.load(MTL_FILE, materials => {
    materials.preload();
    // OBJ Loader
    const objLoader = new THREE.OBJLoader();
    objLoader.setMaterials(materials);
    objLoader.setPath(PATH);
    objLoader.load(OBJ_FILE, object => {
        for(let child of object.children) {
            child.material.side = THREE.DoubleSide
        }

    }, onProgress, onError);
});

Answer 1

I had a similar issue when I was trying to load up a JSON object. This eventually worked for me:

this.state = {
  geometry: { vertices: [], faces: [] faceVertexUvs: []}
};

//in componentDidMount 
const loader = new THREE.JSONLoader();
loader.load("new-origin.json", geometry => {
  geometry.center();
  this.setState({ geometry: geometry });
});

//in my render
<scene>
  <perspectiveCamera
    name="camera"
    fov={45}
    aspect={width / height}
    near={0.1}
    far={10000}
    position={this.cameraPosition}
   />
  <mesh
    rotation={this.state.cubeRotation}
    position={this.meshPosition}>
      <geometry
         vertices={this.state.geometry.vertices}
         faces={this.state.geometry.faces}
         faceVertexUvs={this.state.geometry.faceVertexUvs}
      />
      <meshLambertMaterial />
  </mesh>
</scene>

One thing you really need to watch out for is that you don't want to render ANYTHING until everything is loaded up. So I have a conditional before my return in render that checks if this.state.geometry is actually loaded before I render the React3 Component.

I found https://tweedegolf.nl/blog/14/react-and-threejs very helpful as well, though I ultimately didn't go that route.