Three.js+React实现3D开放世界小游戏

import * as THREE from 'three';
import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader';
import CANNON from 'cannon';
import CannonHelper from './scripts/CannonHelper';
import JoyStick from './scripts/JoyStick';

(<div id="metaverse">
  <canvas className='webgl'></canvas>
  <div className='tool'>
    <div className='countdown'>{ this.state.countdown }</div>
    <button className='reset_button' onClick={this.resetGame}>时光倒流</button>
    <p className='hint'>站得越高看得越远</p>
  </div>
  { this.state.showLoading ? (<div className='loading'>
    <div className='box'>
      <p className='progress'>{this.state.loadingProcess} %</p>
      <p className='description'>游戏描述</p>
      <button className='start_button' style={{'visibility': this.state.loadingProcess === 100 ? 'visible' : 'hidden'}} onClick={this.startGame}>开始游戏</button>
    </div>
  </div>) : '' }
  { this.state.showResult ? (<div className='result'>
    <div className='box'>
      <p className='text'>{ this.state.resultText }</p>
      <button className='button' onClick={this.resetGame}>再试一次</button>
      <button className='button' onClick={this.discover}>自由探索</button>
    </div>
  </div>) : '' }
</div>)

state = {
  loadingProcess: 0,
  showLoading: true,
  showResult: false,
  resultText: '失败',
  countdown: 60,
  freeDiscover: false
}

const renderer = new THREE.WebGLRenderer({
  canvas: document.querySelector('canvas.webgl'),
  antialias: true,
  alpha: true
});
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setPixelRatio(Math.min(window.devicePixelRatio, 2));
renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap;
const scene = new THREE.Scene();
// 添加主相机
const camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, .01, 100000);
camera.position.set(1, 1, -1);
camera.lookAt(scene.position);
// 添加环境光
const ambientLight = new THREE.AmbientLight(0xffffff, .4);
scene.add(ambientLight)
// 添加平行光
var light = new THREE.DirectionalLight(0xffffff, 1);
light.position.set(1, 1, 1).nORMalize();
scene.add(light);

// 初始化物理世界
const world = new CANNON.World();
// 在多个步骤的任意轴上测试刚体的碰撞
world.broadphase = new CANNON.SAPBroadphase(world);
// 设置物理世界的重力为沿y轴向上-10米每二次方秒
world.gravity.set(0, -10, 0);
// 创建默认联系材质
world.defaultContactMaterial.friction = 0;
const groundMaterial = new CANNON.Material("groundMaterial");
const wheelMaterial = new CANNON.Material("wheelMaterial");
const wheelGroundContactMaterial = new CANNON.ContactMaterial(wheelMaterial, groundMaterial, {
  // 摩擦系数
  friction: 0,
  // 恢复系数
  restitution: 0,
  // 接触刚度
  contactEquationStiffness: 1000
});
world.addContactMaterial(wheelGroundContactMaterial);

const textureLoader = new THREE.TextureLoader();
const shaderPoint = THREE.ShaderLib.points;
const uniforms = THREE.UniformsUtils.clone(shaderPoint.uniforms);
uniforms.map.value = textureLoader.load(snowflakeTexture);
for (let i = 0; i < 1000; i++) {
  sparkGeometry.vertices.push(new THREE.Vector3());
}
const sparks = new THREE.Points(new THREE.Geometry(), new THREE.PointsMaterial({
  size: 2,
  color: new THREE.Color(0xffffff),
  map: uniforms.map.value,
  blending: THREE.AdditiveBlending,
  depthWrite: false,
  transparent: true,
  opacity: 0.75
}));
sparks.scale.set(1, 1, 1);
sparks.geometry.vertices.map(spark => {
  spark.y = randnum(30, 40);
  spark.x = randnum(-500, 500);
  spark.z = randnum(-500, 500);
  return true;
});
scene.add(sparks);

const cannonHelper = new CannonHelper(scene);
var sizeX = 128, sizeY = 128, minHeight = 0, maxHeight = 60, check = null;
Promise.all([
  // 加载高度图
  img2matrix.fromUrl(heightMapImage, sizeX, sizeY, minHeight, maxHeight)(),
]).then(function (data) {
  var matrix = data[0];
  // 地形体
  const terrainBody = new CANNON.Body({ mass: 0 });
  // 地形形状
  const terrainShape = new CANNON.Heightfield(matrix, { elementSize: 10 });
  terrainBody.addShape(terrainShape);
  // 地形位置
  terrainBody.position.set(-sizeX * terrainShape.elementSize / 2, -10, sizeY * terrainShape.elementSize / 2);
  // 设置从轴角度
  terrainBody.quaterNIOn.setFromAxisAngle(new CANNON.Vec3(1, 0, 0), -Math.PI / 2);
  world.add(terrainBody);
  // 将生成的地形刚体可视化
  cannonHelper.addVisual(terrainBody, 'landscape');
  var raycastHelperGeometry = new THREE.CylinderGeometry(0, 1, 5, 1.5);
  raycastHelperGeometry.translate(0, 0, 0);
  raycastHelperGeometry.rotateX(Math.PI / 2);
  var raycastHelperMesh = new THREE.Mesh(raycastHelperGeometry, new THREE.MeshNormalMaterial());
  scene.add(raycastHelperMesh);
  // 使用 Raycaster检测并更新模型在地形上的位置
  check = () => {
    var raycaster = new THREE.Raycaster(target.position, new THREE.Vector3(0, -1, 0));
    var intersects = raycaster.intersectObject(terrainBody.threemesh.children[0]);
    if (intersects.length > 0) {
      raycastHelperMesh.position.set(0, 0, 0);
      raycastHelperMesh.lookAt(intersects[0].face.normal);
      raycastHelperMesh.position.copy(intersects[0].point);
    }
    target.position.y = intersects && intersects[0] ? intersects[0].point.y + 0.1 : 30;
    var raycaster2 = new THREE.Raycaster(shelterLocation.position, new THREE.Vector3(0, -1, 0));
    var intersects2 = raycaster2.intersectObject(terrainBody.threemesh.children[0]);
    shelterLocation.position.y = intersects2 && intersects2[0] ? intersects2[0].point.y + .5 : 30;
    shelterLight.position.y = shelterLocation.position.y + 50;
    shelterLight.position.x = shelterLocation.position.x + 5
    shelterLight.position.z = shelterLocation.position.z;
  }
});

Heightfield(data, options)

const loadingManager = new THREE.LoadingManager();
loadingManager.onProgress = async (url, loaded, total) => {
  this.setState({ loadingProcess: Math.floor(loaded / total * 100) });
};

const shelterGeometry = new THREE.BoxBufferGeometry(0.15, 2, 0.15);
const shelterLocation = new THREE.Mesh(shelterGeometry, new THREE.MeshNormalMaterial({
  transparent: true,
  opacity: 0
}));
shelterLocation.position.set(this.shelterPosition.x, this.shelterPosition.y, this.shelterPosition.z);
shelterLocation.rotateY(Math.PI);
scene.add(shelterLocation);
// 加载模型
gltfLoader.load(Shelter, mesh => {
  mesh.scene.traverse(child => {
    child.castShadow = true;
  });
  mesh.scene.scale.set(5, 5, 5);
  mesh.scene.position.y = -.5;
  shelterLocation.add(mesh.scene)
});
// 添加光源
const shelterPointLight = new THREE.PointLight(0x1089ff, 2);
shelterPointLight.position.set(0, 0, 0);
shelterLocation.add(shelterPointLight);
const shelterLight = new THREE.DirectionalLight(0xffffff, 0);
shelterLight.position.set(0, 0, 0);
shelterLight.castShadow = true;
shelterLight.target = shelterLocation;
scene.add(shelterLight);

var geometry = new THREE.BoxBufferGeometry(.5, 1, .5);
geometry.applyMatrix4(new THREE.Matrix4().makeTranslation(0, .5, 0));
const target = new THREE.Mesh(geometry, new THREE.MeshNormalMaterial({
  transparent: true,
  opacity: 0
}));
scene.add(target);

var mixers = [], clip1, clip2;
const gltfLoader = new GLTFLoader(loadingManager);
gltfLoader.load(foxModel, mesh => {
  mesh.scene.traverse(child => {
    if (child.isMesh) {
      child.castShadow = true;
      child.material.side = THREE.DoubleSide;
    }
  });
  var player = mesh.scene;
  player.position.set(this.playPosition.x, this.playPosition.y, this.playPosition.z);
  player.scale.set(.008, .008, .008);
  target.add(player);
  var mixer = new THREE.AnimationMixer(player);
  clip1 = mixer.clipAction(mesh.animations[0]);
  clip2 = mixer.clipAction(mesh.animations[1]);
  clip2.timeScale = 1.6;
  mixers.push(mixer);
});

const directionalLight = new THREE.DirectionalLight(new THREE.Color(0xffffff), .5);
directionalLight.position.set(0, 1, 0);
directionalLight.castShadow = true;
directionalLight.target = target;
target.add(directionalLight);

var setup = { forward: 0, turn: 0 };
new JoyStick({ onMove: (forward, turn) => {
  setup.forward = forward;
  setup.turn = -turn;
}});
const updateDrive = (forward = setup.forward, turn = setup.turn) => {
  let maxSteerVal = 0.05;
  let maxForce = .15;
  let force = maxForce * forward;
  let steer = maxSteerVal * turn;
  if (forward !== 0) {
    target.translateZ(force);
    clip2 && clip2.play();
    clip1 && clip1.stop();
  } else {
    clip2 && clip2.stop();
    clip1 && clip1.play();
  }
  target.rotateY(steer);
}
// 生成第三人称视角
const followCamera = new THREE.Object3D();
followCamera.position.copy(camera.position);
scene.add(followCamera);
followCamera.parent = target;
const updateCamera = () => {
  if (followCamera) {
    camera.position.lerp(followCamera.getWorldPosition(new THREE.Vector3()), 0.1);
    camera.lookAt(target.position.x, target.position.y + .5, target.position.z);
  }
}

var clock = new THREE.Clock();
var lastTime;
var fixedTimeStep = 1.0 / 60.0;
const animate = () => {
  updateCamera();
  updateDrive();
  let delta = clock.getDelta();
  mixers.map(x => x.update(delta));
  let now = Date.now();
  lastTime === undefined && (lastTime = now);
  let dt = (Date.now() - lastTime) / 1000.0;
  lastTime = now;
  world.step(fixedTimeStep, dt);
  cannonHelper.updateBodies(world);
  check && check();
  renderer.render(scene, camera);
  requestAnimationFrame(animate);
};

window.addEventListener('resize', () => {
  var width = window.innerWidth, height = window.innerHeight;
  renderer.setSize(width, height);
  camera.aspect = width / height;
  camera.updateProjectionMatrix();
}, false);

startGame = () => {
  this.setState({
    showLoading : false,
    showResult: false,
    countdown: 60,
    resultText: '失败',
    freeDiscover: false
  },() => {
    this.interval = setInterval(() => {
      if (this.state.countdown > 0) {
        this.setState({
          countdown: --this.state.countdown
        });
      } else {
        clearInterval(this.interval)
        this.setState({
          showResult: true
        });
      }
    }, 1000);
  });
}
resetGame = () => {
  this.player.position.set(this.playPosition.x, this.playPosition.y, this.playPosition.z);
  this.target.rotation.set(0, 0, 0);
  this.target.position.set(0, 0, 0);
  this.camera.position.set(1, 1, -1);
  this.startGame();
}
discover = () => {
  this.setState({
    freeDiscover: true,
    showResult: false,
    countdown: 60
  }, () => {
    clearInterval(this.interval);
  });
}

background rgba(0, 67, 170, .5)
backdrop-filter blur(10px)
filter drop-shadow(0px 1px 1px rgba(0, 0, 0, .25))