Question

我正在尝试在React应用程序中使用three.js，但是即使Three.js文档中的基本示例也无法加载到画布上。

我首先使用可以正常工作的示例制作了vanilla.js sandbox实现。然后，我将其移植到一个无法正常工作的react + three.js最小sandbox实现中。

任何人都可以看一下并指出正确的方向吗？

class Viewer extends Component {
    state = {};

    scene = null;

    camera = null;

    renderer = new WebGLRenderer();

    inst = 0;

    viewerRef = React.createRef();

    componentDidMount() {
        const { domElement } = this.renderer;
        this.scene = new Scene();
        this.scene.background = new Color("#ccc");
        this.camera = new Camera(
        75,
        domElement.innerWidth / domElement.innerHeight,
        0.1,
        1000
        );
        this.renderer.setSize(domElement.innerWidth, domElement.innerHeight);
        this.viewerRef.current.appendChild(this.renderer.domElement);
        const geometry = new BoxGeometry(1, 1, 1);
        const material = new MeshBasicMaterial({ color: 0x05ff00 });
        const cube = new Mesh(geometry, material);

        this.scene.add(cube);

        this.camera.position.z = 5;
        this.display();
    }

    display = () => {
        this.renderer.render(this.scene, this.camera);
        requestAnimationFrame(this.display);
    };

    render = () => <div className="viewer" ref={this.viewerRef} />;
}

Answer 1

这里是CodeSandBox，可与Three.js的基本React包装器代码一起使用。它还具有THREE.OrbitControls集成并可以在调整大小的代码上缩放：

https://codesandbox.io/s/github/supromikali/react-three-demo

实时演示：https://31yp61zxq6.codesandbox.io/

以下是上面列出的链接对您不起作用的情况下的完整代码段：

index.js代码

import React, { Component } from "react";
import ReactDOM from "react-dom";
import THREE from "./three";


class App extends Component {
    componentDidMount() {


        // BASIC THREE.JS THINGS: SCENE, CAMERA, RENDERER
        // Three.js Creating a scene tutorial
        // https://threejs.org/docs/index.html#manual/en/introduction/Creating-a-scene
        var scene = new THREE.Scene();
        var camera = new THREE.PerspectiveCamera(
            75,
            window.innerWidth / window.innerHeight,
            0.1,
            1000
        );
        camera.position.z = 5;

        var renderer = new THREE.WebGLRenderer();
        renderer.setSize(window.innerWidth, window.innerHeight);



        // MOUNT INSIDE OF REACT
        this.mount.appendChild(renderer.domElement); // mount a scene inside of React using a ref



        // CAMERA CONTROLS
        // https://threejs.org/docs/index.html#examples/controls/OrbitControls
        this.controls = new THREE.OrbitControls(camera);



        // ADD CUBE AND LIGHTS
        // https://threejs.org/docs/index.html#api/en/geometries/BoxGeometry
        // https://threejs.org/docs/scenes/geometry-browser.html#BoxGeometry
        var geometry = new THREE.BoxGeometry(2, 2, 2);
        var material = new THREE.MeshPhongMaterial( {
            color: 0x156289,
            emissive: 0x072534,
            side: THREE.DoubleSide,
            flatShading: true
        } );
        var cube = new THREE.Mesh(geometry, material);
        scene.add(cube);

        var lights = [];
        lights[ 0 ] = new THREE.PointLight( 0xffffff, 1, 0 );
        lights[ 1 ] = new THREE.PointLight( 0xffffff, 1, 0 );
        lights[ 2 ] = new THREE.PointLight( 0xffffff, 1, 0 );

        lights[ 0 ].position.set( 0, 200, 0 );
        lights[ 1 ].position.set( 100, 200, 100 );
        lights[ 2 ].position.set( - 100, - 200, - 100 );

        scene.add( lights[ 0 ] );
        scene.add( lights[ 1 ] );
        scene.add( lights[ 2 ] );



        // SCALE ON RESIZE

        // Check "How can scene scale be preserved on resize?" section of Three.js FAQ
        // https://threejs.org/docs/index.html#manual/en/introduction/FAQ

        // code below is taken from Three.js fiddle
        // http://jsfiddle.net/Q4Jpu/

        // remember these initial values
        var tanFOV = Math.tan( ( ( Math.PI / 180 ) * camera.fov / 2 ) );
        var windowHeight = window.innerHeight;

        window.addEventListener( 'resize', onWindowResize, false );

        function onWindowResize( event ) {

            camera.aspect = window.innerWidth / window.innerHeight;

            // adjust the FOV
            camera.fov = ( 360 / Math.PI ) * Math.atan( tanFOV * ( window.innerHeight / windowHeight ) );

            camera.updateProjectionMatrix();
            camera.lookAt( scene.position );

            renderer.setSize( window.innerWidth, window.innerHeight );
            renderer.render( scene, camera );

        }



        // ANIMATE THE SCENE
        var animate = function() {
            requestAnimationFrame(animate);

            cube.rotation.x += 0.01;
            cube.rotation.y += 0.01;

            renderer.render(scene, camera);
        };

        animate();
    }
    render() {
        return <div ref={ref => (this.mount = ref)} />;
    }
}

const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

three.js代码（THREE.OrbitControls导入）

import * as THREE from 'three';


window.THREE = THREE; // THREE.OrbitControls expects THREE to be a global object
require('three/examples/js/controls/OrbitControls');


export default {...THREE, OrbitControls: window.THREE.OrbitControls};

结果应如下所示：

Answer 2

您的沙箱目前存在一些问题，不一定与React有关。

Float.random(in: 0.0...1.0)和innerWidth。 innerHeight和clientWidth可能是您要获取dom元素尺寸的字段。
在将画布添加到文档之前要先对其进行读取，这意味着该元素的尺寸将始终为clientHeight。在计算相机的宽高比并设置渲染大小之前，请先插入元素。
0 0不能直接使用。 The docs specify it as an abstract base class for cameras-改用Camera。

这是经过上述修复的代码示例

PerspectiveCamera

希望有帮助！

Answer 3

我不确定为什么没人提到react-three-fiber。这是ThreeJS的React渲染器。

最好的部分是，使用rollupjs，我们甚至可以摇晃很多不必要的代码，而这些代码我们不会在React ThreeJS应用程序中使用。另外，以期望的方式使用react-three-fiber，我们的ThreeJS动画可以达到60FPS F

要学习基础知识，只需看看react-three-fiber Examples

如何在React中使用three.js

3 个答案: