無法通過react-three-renderer加載.mtl和.obj

Question

我正在嘗試通過react-three-renderer加載.obj和.mtl，但是我在加載模型時錯過了機會。 目前，我能夠在div中渲染一個多維數據集。 但是，我想用我的.obj模型替換多維數據集。

安裝：

npm install --save react@15.6.1 react-dom@15.6.1 three@0.86.0
npm install --save react-three-renderer
npm install --save three-obj-loader
npm install --save three-mtl-loader

用法：div內的多維數據集

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;

預期的3D模型.obj .mtl，但在何處添加此代碼？

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

嘗試加載JSON對象時，我遇到了類似的問題。 最終這對我有用：

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>

您真正需要注意的一件事是，在所有內容加載完畢之前，您不希望呈現任何內容。 所以我在返回渲染之前有一個條件，可以在渲染React3組件之前檢查this.state.geometry是否實際加載。

我發現https://tweedegolf.nl/blog/14/react-and-threejs也非常有幫助，盡管我最終沒有走這條路。