前言

Three.js 是一款运行在浏览器中的 3D 引擎，你可以用它创建各种三维场景，包括了摄影机、光影、材质等各种对象。

一个典型的 Three.js 程序至少要包括渲染器（Renderer）、场景（Scene）、照相机（Camera），以及你在场景中创建的物体。

Three.js相关文档：http://docs.thingjs.com/

一、Three.js的使用

安装第三方包：npm i --save threejs-miniprogram

1.正方体的绘制

<view style="display:inline-block;">
  <button size="mini" type="primary" class="btn" data-action="Walking" bindtap="play">走</button>
  <button size="mini" type="primary" class="btn"  data-action="WalkJump" bindtap="play">跳</button>
  <button size="mini" type="primary" class="btn"  data-action="Sitting" bindtap="play">坐</button>
  <button size="mini" type="primary" class="btn"  data-action="Standing" bindtap="play">站</button>
</view>
<canvas
  type="webgl"
  id="webgl"
  style="width: 100%; height: 450px;"
  bindtouchstart="touchStart"
  bindtouchmove="touchMove"
  bindtouchend="touchEnd"
></canvas>

import { createScopedThreejs } from 'threejs-miniprogram'
const { renderCube } = require('../../../lib/test-cases/cube')

const app = getApp()

Page({
  data: {},
  onLoad: function () {
    wx.createSelectorQuery()
      .select('#webgl')
      .node()
      .exec((res) => {
        const canvas = res[0].node
        this.canvas = canvas
        const THREE = createScopedThreejs(canvas)
        
        renderCube(canvas, THREE)
      })
  },
  play(e){
    let action = e.currentTarget.dataset.action
    this.fadeToAction(action)
  },
  touchStart(e) {
    this.canvas.dispatchTouchEvent({...e, type:'touchstart'})
  },
  touchMove(e) {
    this.canvas.dispatchTouchEvent({...e, type:'touchmove'})
  },
  touchEnd(e) {
    this.canvas.dispatchTouchEvent({...e, type:'touchend'})
  }
})

二、正方体相关js文件

import registerOrbit from "./orbit"

export function renderCube(canvas, THREE) {
  var camera, scene, renderer,controls;
  var mesh;
  init();
  // animate();
  function init() {
    camera = new THREE.PerspectiveCamera(70, canvas.width / canvas.height, 1, 1000);
    camera.position.z = 400;
    scene = new THREE.Scene();
    var texture = new THREE.TextureLoader().load('/static/cubetexture.png');
    var geometry = new THREE.BoxBufferGeometry(200, 200, 200);
    var material = new THREE.MeshBasicMaterial({ map: texture });
    mesh = new THREE.Mesh(geometry, material);
    scene.add(mesh);

    renderer = new THREE.WebGLRenderer({ antialias: true });
    renderer.setPixelRatio(wx.getSystemInfoSync().pixelRatio);
    renderer.setSize(canvas.width, canvas.height);
    renderer.render(scene, camera);

    // 控制鼠标拖拽的
    const { OrbitControls } = registerOrbit(THREE)
    controls = new OrbitControls( camera, renderer.domElement );

    // camera.position.set( 5, 5, 10 );
    controls.update();
    // renderer.render(scene, camera);
    animate()
  }
  function onWindowResize() {
    camera.aspect = window.innerWidth / window.innerHeight;
    camera.updateProjectionMatrix();
    renderer.setSize(canvas.width, canvas.height);
  }
  function animate() {
    canvas.requestAnimationFrame(animate);
    // mesh.rotation.x += 0.005;
    // mesh.rotation.y += 0.01;
    controls.update();
    renderer.render(scene, camera);
  }
}

/**
 * @author qiao / https://github.com/qiao
 * @author mrdoob / http://mrdoob.com
 * @author alteredq / http://alteredqualia.com/
 * @author WestLangley / http://github.com/WestLangley
 * @author erich666 / http://erichaines.com
 * @author ScieCode / http://github.com/sciecode
 */

const registerOrbit = (THREE) => {
	const {
		EventDispatcher,
		MOUSE,
		Quaternion,
		Spherical,
		TOUCH,
		Vector2,
		Vector3
	} = THREE

	// This set of controls performs orbiting, dollying (zooming), and panning.
	// Unlike TrackballControls, it maintains the "up" direction object.up (+Y by default).
	//
	//    Orbit - left mouse / touch: one-finger move
	//    Zoom - middle mouse, or mousewheel / touch: two-finger spread or squish
	//    Pan - right mouse, or left mouse + ctrl/meta/shiftKey, or arrow keys / touch: two-finger move

	var OrbitControls = function (object, domElement) {

		if (domElement === undefined) console.warn('THREE.OrbitControls: The second parameter "domElement" is now mandatory.');
		if (domElement === document) console.error('THREE.OrbitControls: "document" should not be used as the target "domElement". Please use "renderer.domElement" instead.');

		this.object = object;
		this.domElement = domElement;

		// Set to false to disable this control
		this.enabled = true;

		// "target" sets the location of focus, where the object orbits around
		this.target = new Vector3();

		// How far you can dolly in and out ( PerspectiveCamera only )
		this.minDistance = 0;
		this.maxDistance = Infinity;

		// How far you can zoom in and out ( OrthographicCamera only )
		this.minZoom = 0;
		this.maxZoom = Infinity;

		// How far you can orbit vertically, upper and lower limits.
		// Range is 0 to Math.PI radians.
		this.minPolarAngle = 0; // radians
		this.maxPolarAngle = Math.PI; // radians

		// How far you can orbit horizontally, upper and lower limits.
		// If set, must be a sub-interval of the interval [ - Math.PI, Math.PI ].
		this.minAzimuthAngle = -Infinity; // radians
		this.maxAzimuthAngle = Infinity; // radians

		// Set to true to enable damping (inertia)
		// If damping is enabled, you must call controls.update() in your animation loop
		this.enableDamping = false;
		this.dampingFactor = 0.05;

		// This option actually enables dollying in and out; left as "zoom" for backwards compatibility.
		// Set to false to disable zooming
		this.enableZoom = true;
		this.zoomSpeed = 1.0;

		// Set to false to disable rotating
		this.enableRotate = true;
		this.rotateSpeed = 1.0;

		// Set to false to disable panning
		this.enablePan = true;
		this.panSpeed = 1.0;
		this.screenSpacePanning = false; // if true, pan in screen-space
		this.keyPanSpeed = 7.0; // pixels moved per arrow key push

		// Set to true to automatically rotate around the target
		// If auto-rotate is enabled, you must call controls.update() in your animation loop
		this.autoRotate = false;
		this.autoRotateSpeed = 2.0; // 30 seconds per round when fps is 60

		// Set to false to disable use of the keys
		this.enableKeys = true;

		// The four arrow keys
		this.keys = {
			LEFT: 37,
			UP: 38,
			RIGHT: 39,
			BOTTOM: 40
		};

		// Mouse buttons
		this.mouseButtons = {
			LEFT: MOUSE.ROTATE,
			MIDDLE: MOUSE.DOLLY,
			RIGHT: MOUSE.PAN
		};

		// Touch fingers
		this.touches = {
			ONE: TOUCH.ROTATE,
			TWO: TOUCH.DOLLY_PAN
		};

		// for reset
		this.target0 = this.target.clone();
		this.position0 = this.object.position.clone();
		this.zoom0 = this.object.zoom;

		//
		// public methods
		//

		this.getPolarAngle = function () {

			return spherical.phi;

		};

		this.getAzimuthalAngle = function () {

			return spherical.theta;

		};

		this.saveState = function () {

			scope.target0.copy(scope.target);
			scope.position0.copy(scope.object.position);
			scope.zoom0 = scope.object.zoom;

		};

		this.reset = function () {

			scope.target.copy(scope.target0);
			scope.object.position.copy(scope.position0);
			scope.object.zoom = scope.zoom0;

			scope.object.updateProjectionMatrix();
			scope.dispatchEvent(changeEvent);

			scope.update();

			state = STATE.NONE;

		};

		// this method is exposed, but perhaps it would be better if we can make it private...
		this.update = function () {

			var offset = new Vector3();

			// so camera.up is the orbit axis
			var quat = new Quaternion().setFromUnitVectors(object.up, new Vector3(0, 1, 0));
			var quatInverse = quat.clone().inverse();

			var lastPosition = new Vector3();
			var lastQuaternion = new Quaternion();

			return function update() {

				var position = scope.object.position;

				offset.copy(position).sub(scope.target);

				// rotate offset to "y-axis-is-up" space
				offset.applyQuaternion(quat);

				// angle from z-axis around y-axis
				spherical.setFromVector3(offset);

				if (scope.autoRotate && state === STATE.NONE) {

					rotateLeft(getAutoRotationAngle());

				}

				if (scope.enableDamping) {

					spherical.theta += sphericalDelta.theta * scope.dampingFactor;
					spherical.phi += sphericalDelta.phi * scope.dampingFactor;

				} else {

					spherical.theta += sphericalDelta.theta;
					spherical.phi += sphericalDelta.phi;

				}

				// restrict theta to be between desired limits
				spherical.theta = Math.max(scope.minAzimuthAngle, Math.min(scope.maxAzimuthAngle, spherical.theta));

				// restrict phi to be between desired limits
				spherical.phi = Math.max(scope.minPolarAngle, Math.min(scope.maxPolarAngle, spherical.phi));

				spherical.makeSafe();


				spherical.radius *= scale;

				// restrict radius to be between desired limits
				spherical.radius = Math.max(scope.minDistance, Math.min(scope.maxDistance, spherical.radius));

				// move target to panned location

				if (scope.enableDamping === true) {

					scope.target.addScaledVector(panOffset, scope.dampingFactor);

				} else {

					scope.target.add(panOffset);

				}

				offset.setFromSpherical(spherical);

				// rotate offset back to "camera-up-vector-is-up" space
				offset.applyQuaternion(quatInverse);

				position.copy(scope.target).add(offset);

				scope.object.lookAt(scope.target);

				if (scope.enableDamping === true) {

					sphericalDelta.theta *= (1 - scope.dampingFactor);
					sphericalDelta.phi *= (1 - scope.dampingFactor);

					panOffset.multiplyScalar(1 - scope.dampingFactor);

				} else {

					sphericalDelta.set(0, 0, 0);

					panOffset.set(0, 0, 0);

				}

				scale = 1;

				// update condition is:
				// min(camera displacement, camera rotation in radians)^2 > EPS
				// using small-angle approximation cos(x/2) = 1 - x^2 / 8

				if (zoomChanged ||
					lastPosition.distanceToSquared(scope.object.position) > EPS ||
					8 * (1 - lastQuaternion.dot(scope.object.quaternion)) > EPS) {

					scope.dispatchEvent(changeEvent);

					lastPosition.copy(scope.object.position);
					lastQuaternion.copy(scope.object.quaternion);
					zoomChanged = false;

					return true;

				}

				return false;

			};

		}();

		this.dispose = function () {

			scope.domElement.removeEventListener('contextmenu', onContextMenu, false);
			scope.domElement.removeEventListener('mousedown', onMouseDown, false);
			scope.domElement.removeEventListener('wheel', onMouseWheel, false);

			scope.domElement.removeEventListener('touchstart', onTouchStart, false);
			scope.domElement.removeEventListener('touchend', onTouchEnd, false);
			scope.domElement.removeEventListener('touchmove', onTouchMove, false);

			document.removeEventListener('mousemove', onMouseMove, false);
			document.removeEventListener('mouseup', onMouseUp, false);

			scope.domElement.removeEventListener('keydown', onKeyDown, false);

			//scope.dispatchEvent( { type: 'dispose' } ); // should this be added here?

		};

		//
		// internals
		//

		var scope = this;

		var changeEvent = {
			type: 'change'
		};
		var startEvent = {
			type: 'start'
		};
		var endEvent = {
			type: 'end'
		};

		var STATE = {
			NONE: -1,
			ROTATE: 0,
			DOLLY: 1,
			PAN: 2,
			TOUCH_ROTATE: 3,
			TOUCH_PAN: 4,
			TOUCH_DOLLY_PAN: 5,
			TOUCH_DOLLY_ROTATE: 6
		};

		var state = STATE.NONE;

		var EPS = 0.000001;

		// current position in spherical coordinates
		var spherical = new Spherical();
		var sphericalDelta = new Spherical();

		var scale = 1;
		var panOffset = new Vector3();
		var zoomChanged = false;

		var rotateStart = new Vector2();
		var rotateEnd = new Vector2();
		var rotateDelta = new Vector2();

		var panStart = new Vector2();
		var panEnd = new Vector2();
		var panDelta = new Vector2();

		var dollyStart = new Vector2();
		var dollyEnd = new Vector2();
		var dollyDelta = new Vector2();

		function getAutoRotationAngle() {

			return 2 * Math.PI / 60 / 60 * scope.autoRotateSpeed;

		}

		function getZoomScale() {

			return Math.pow(0.95, scope.zoomSpeed);

		}

		function rotateLeft(angle) {

			sphericalDelta.theta -= angle;

		}

		function rotateUp(angle) {

			sphericalDelta.phi -= angle;

		}

		var panLeft = function () {

			var v = new Vector3();

			return function panLeft(distance, objectMatrix) {

				v.setFromMatrixColumn(objectMatrix, 0); // get X column of objectMatrix
				v.multiplyScalar(-distance);

				panOffset.add(v);

			};

		}();

		var panUp = function () {

			var v = new Vector3();

			return function panUp(distance, objectMatrix) {

				if (scope.screenSpacePanning === true) {

					v.setFromMatrixColumn(objectMatrix, 1);

				} else {

					v.setFromMatrixColumn(objectMatrix, 0);
					v.crossVectors(scope.object.up, v);

				}

				v.multiplyScalar(distance);

				panOffset.add(v);

			};

		}();

		// deltaX and deltaY are in pixels; right and down are positive
		var pan = function () {

			var offset = new Vector3();

			return function pan(deltaX, deltaY) {

				var element = scope.domElement;

				if (scope.object.isPerspectiveCamera) {

					// perspective
					var position = scope.object.position;
					offset.copy(position).sub(scope.target);
					var targetDistance = offset.length();

					// half of the fov is center to top of screen
					targetDistance *= Math.tan((scope.object.fov / 2) * Math.PI / 180.0);

					// we use only clientHeight here so aspect ratio does not distort speed
					panLeft(2 * deltaX * targetDistance / element.clientHeight, scope.object.matrix);
					panUp(2 * deltaY * targetDistance / element.clientHeight, scope.object.matrix);

				} else if (scope.object.isOrthographicCamera) {

					// orthographic
					panLeft(deltaX * (scope.object.right - scope.object.left) / scope.object.zoom / element.clientWidth, scope.object.matrix);
					panUp(deltaY * (scope.object.top - scope.object.bottom) / scope.object.zoom / element.clientHeight, scope.object.matrix);

				} else {

					// camera neither orthographic nor perspective
					console.warn('WARNING: OrbitControls.js encountered an unknown camera type - pan disabled.');
					scope.enablePan = false;

				}

			};

		}();

		function dollyOut(dollyScale) {
			if (scope.object.isPerspectiveCamera) {

				scale /= dollyScale;

			} else if (scope.object.isOrthographicCamera) {

				scope.object.zoom = Math.max(scope.minZoom, Math.min(scope.maxZoom, scope.object.zoom * dollyScale));
				scope.object.updateProjectionMatrix();
				zoomChanged = true;

			} else {

				console.warn('WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.');
				scope.enableZoom = false;

			}

		}

		function dollyIn(dollyScale) {

			if (scope.object.isPerspectiveCamera) {

				scale *= dollyScale;

			} else if (scope.object.isOrthographicCamera) {

				scope.object.zoom = Math.max(scope.minZoom, Math.min(scope.maxZoom, scope.object.zoom / dollyScale));
				scope.object.updateProjectionMatrix();
				zoomChanged = true;

			} else {

				console.warn('WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.');
				scope.enableZoom = false;

			}

		}

		//
		// event callbacks - update the object state
		//

		function handleMouseDownRotate(event) {

			rotateStart.set(event.clientX, event.clientY);

		}

		function handleMouseDownDolly(event) {

			dollyStart.set(event.clientX, event.clientY);

		}

		function handleMouseDownPan(event) {

			panStart.set(event.clientX, event.clientY);

		}

		function handleMouseMoveRotate(event) {

			rotateEnd.set(event.clientX, event.clientY);

			rotateDelta.subVectors(rotateEnd, rotateStart).multiplyScalar(scope.rotateSpeed);

			var element = scope.domElement;

			rotateLeft(2 * Math.PI * rotateDelta.x / element.clientHeight); // yes, height

			rotateUp(2 * Math.PI * rotateDelta.y / element.clientHeight);

			rotateStart.copy(rotateEnd);

			scope.update();

		}

		function handleMouseMoveDolly(event) {

			dollyEnd.set(event.clientX, event.clientY);

			dollyDelta.subVectors(dollyEnd, dollyStart);

			if (dollyDelta.y > 0) {

				dollyOut(getZoomScale());

			} else if (dollyDelta.y < 0) {

				dollyIn(getZoomScale());

			}

			dollyStart.copy(dollyEnd);

			scope.update();

		}

		function handleMouseMovePan(event) {

			panEnd.set(event.clientX, event.clientY);

			panDelta.subVectors(panEnd, panStart).multiplyScalar(scope.panSpeed);

			pan(panDelta.x, panDelta.y);

			panStart.copy(panEnd);

			scope.update();

		}

		function handleMouseUp( /*event*/ ) {

			// no-op

		}

		function handleMouseWheel(event) {

			if (event.deltaY < 0) {

				dollyIn(getZoomScale());

			} else if (event.deltaY > 0) {

				dollyOut(getZoomScale());

			}

			scope.update();

		}

		function handleKeyDown(event) {

			var needsUpdate = false;

			switch (event.keyCode) {

				case scope.keys.UP:
					pan(0, scope.keyPanSpeed);
					needsUpdate = true;
					break;

				case scope.keys.BOTTOM:
					pan(0, -scope.keyPanSpeed);
					needsUpdate = true;
					break;

				case scope.keys.LEFT:
					pan(scope.keyPanSpeed, 0);
					needsUpdate = true;
					break;

				case scope.keys.RIGHT:
					pan(-scope.keyPanSpeed, 0);
					needsUpdate = true;
					break;

			}

			if (needsUpdate) {

				// prevent the browser from scrolling on cursor keys
				event.preventDefault();

				scope.update();

			}


		}

		function handleTouchStartRotate(event) {

			if (event.touches.length == 1) {

				rotateStart.set(event.touches[0].pageX, event.touches[0].pageY);

			} else {

				var x = 0.5 * (event.touches[0].pageX + event.touches[1].pageX);
				var y = 0.5 * (event.touches[0].pageY + event.touches[1].pageY);

				rotateStart.set(x, y);

			}

		}

		function handleTouchStartPan(event) {

			if (event.touches.length == 1) {

				panStart.set(event.touches[0].pageX, event.touches[0].pageY);

			} else {

				var x = 0.5 * (event.touches[0].pageX + event.touches[1].pageX);
				var y = 0.5 * (event.touches[0].pageY + event.touches[1].pageY);

				panStart.set(x, y);

			}

		}

		function handleTouchStartDolly(event) {

			var dx = event.touches[0].pageX - event.touches[1].pageX;
			var dy = event.touches[0].pageY - event.touches[1].pageY;

			var distance = Math.sqrt(dx * dx + dy * dy);

			dollyStart.set(0, distance);

		}

		function handleTouchStartDollyPan(event) {

			if (scope.enableZoom) handleTouchStartDolly(event);

			if (scope.enablePan) handleTouchStartPan(event);

		}

		function handleTouchStartDollyRotate(event) {

			if (scope.enableZoom) handleTouchStartDolly(event);

			if (scope.enableRotate) handleTouchStartRotate(event);

		}

		function handleTouchMoveRotate(event) {
			if (event.touches.length == 1) {

				rotateEnd.set(event.touches[0].pageX, event.touches[0].pageY);

			} else {

				var x = 0.5 * (event.touches[0].pageX + event.touches[1].pageX);
				var y = 0.5 * (event.touches[0].pageY + event.touches[1].pageY);

				rotateEnd.set(x, y);

			}

			rotateDelta.subVectors(rotateEnd, rotateStart).multiplyScalar(scope.rotateSpeed);

			var element = scope.domElement;

			rotateLeft(2 * Math.PI * rotateDelta.x / element.clientHeight); // yes, height

			rotateUp(2 * Math.PI * rotateDelta.y / element.clientHeight);

			rotateStart.copy(rotateEnd);

		}

		function handleTouchMovePan(event) {

			if (event.touches.length == 1) {

				panEnd.set(event.touches[0].pageX, event.touches[0].pageY);

			} else {

				var x = 0.5 * (event.touches[0].pageX + event.touches[1].pageX);
				var y = 0.5 * (event.touches[0].pageY + event.touches[1].pageY);

				panEnd.set(x, y);

			}
			panDelta.subVectors(panEnd, panStart).multiplyScalar(scope.panSpeed);

			pan(panDelta.x, panDelta.y);

			panStart.copy(panEnd);

		}

		function handleTouchMoveDolly(event) {

			var dx = event.touches[0].pageX - event.touches[1].pageX;
			var dy = event.touches[0].pageY - event.touches[1].pageY;

			var distance = Math.sqrt(dx * dx + dy * dy);

			dollyEnd.set(0, distance);

			dollyDelta.set(0, Math.pow(dollyEnd.y / dollyStart.y, scope.zoomSpeed));

			dollyOut(dollyDelta.y);

			dollyStart.copy(dollyEnd);

		}

		function handleTouchMoveDollyPan(event) {

			if (scope.enableZoom) handleTouchMoveDolly(event);

			if (scope.enablePan) handleTouchMovePan(event);

		}

		function handleTouchMoveDollyRotate(event) {

			if (scope.enableZoom) handleTouchMoveDolly(event);

			if (scope.enableRotate) handleTouchMoveRotate(event);

		}

		function handleTouchEnd( /*event*/ ) {

			// no-op

		}

		//
		// event handlers - FSM: listen for events and reset state
		//

		function onMouseDown(event) {

			if (scope.enabled === false) return;

			// Prevent the browser from scrolling.
			event.preventDefault();

			// Manually set the focus since calling preventDefault above
			// prevents the browser from setting it automatically.

			scope.domElement.focus ? scope.domElement.focus() : window.focus();

			var mouseAction;

			switch (event.button) {

				case 0:

					mouseAction = scope.mouseButtons.LEFT;
					break;

				case 1:

					mouseAction = scope.mouseButtons.MIDDLE;
					break;

				case 2:

					mouseAction = scope.mouseButtons.RIGHT;
					break;

				default:

					mouseAction = -1;

			}

			switch (mouseAction) {

				case MOUSE.DOLLY:

					if (scope.enableZoom === false) return;

					handleMouseDownDolly(event);

					state = STATE.DOLLY;

					break;

				case MOUSE.ROTATE:

					if (event.ctrlKey || event.metaKey || event.shiftKey) {

						if (scope.enablePan === false) return;

						handleMouseDownPan(event);

						state = STATE.PAN;

					} else {

						if (scope.enableRotate === false) return;

						handleMouseDownRotate(event);

						state = STATE.ROTATE;

					}

					break;

				case MOUSE.PAN:

					if (event.ctrlKey || event.metaKey || event.shiftKey) {

						if (scope.enableRotate === false) return;

						handleMouseDownRotate(event);

						state = STATE.ROTATE;

					} else {

						if (scope.enablePan === false) return;

						handleMouseDownPan(event);

						state = STATE.PAN;

					}

					break;

				default:

					state = STATE.NONE;

			}

			if (state !== STATE.NONE) {

				document.addEventListener('mousemove', onMouseMove, false);
				document.addEventListener('mouseup', onMouseUp, false);

				scope.dispatchEvent(startEvent);

			}

		}

		function onMouseMove(event) {

			if (scope.enabled === false) return;

			event.preventDefault();

			switch (state) {

				case STATE.ROTATE:

					if (scope.enableRotate === false) return;

					handleMouseMoveRotate(event);

					break;

				case STATE.DOLLY:

					if (scope.enableZoom === false) return;

					handleMouseMoveDolly(event);

					break;

				case STATE.PAN:

					if (scope.enablePan === false) return;

					handleMouseMovePan(event);

					break;

			}

		}

		function onMouseUp(event) {

			if (scope.enabled === false) return;

			handleMouseUp(event);

			document.removeEventListener('mousemove', onMouseMove, false);
			document.removeEventListener('mouseup', onMouseUp, false);

			scope.dispatchEvent(endEvent);

			state = STATE.NONE;

		}

		function onMouseWheel(event) {

			if (scope.enabled === false || scope.enableZoom === false || (state !== STATE.NONE && state !== STATE.ROTATE)) return;

			event.preventDefault();
			event.stopPropagation();

			scope.dispatchEvent(startEvent);

			handleMouseWheel(event);

			scope.dispatchEvent(endEvent);

		}

		function onKeyDown(event) {

			if (scope.enabled === false || scope.enableKeys === false || scope.enablePan === false) return;

			handleKeyDown(event);

		}

		function onTouchStart(event) {

			if (scope.enabled === false) return;

			event.preventDefault(); // prevent scrolling

			switch (event.touches.length) {

				case 1:

					switch (scope.touches.ONE) {

						case TOUCH.ROTATE:

							if (scope.enableRotate === false) return;

							handleTouchStartRotate(event);

							state = STATE.TOUCH_ROTATE;

							break;

						case TOUCH.PAN:

							if (scope.enablePan === false) return;

							handleTouchStartPan(event);

							state = STATE.TOUCH_PAN;

							break;

						default:

							state = STATE.NONE;

					}

					break;

				case 2:

					switch (scope.touches.TWO) {

						case TOUCH.DOLLY_PAN:

							if (scope.enableZoom === false && scope.enablePan === false) return;

							handleTouchStartDollyPan(event);

							state = STATE.TOUCH_DOLLY_PAN;

							break;

						case TOUCH.DOLLY_ROTATE:

							if (scope.enableZoom === false && scope.enableRotate === false) return;

							handleTouchStartDollyRotate(event);

							state = STATE.TOUCH_DOLLY_ROTATE;

							break;

						default:

							state = STATE.NONE;

					}

					break;

				default:

					state = STATE.NONE;

			}

			if (state !== STATE.NONE) {

				scope.dispatchEvent(startEvent);

			}

		}

		function onTouchMove(event) {
			if (scope.enabled === false) return;

			event.preventDefault(); // prevent scrolling
			event.stopPropagation();

			switch (state) {

				case STATE.TOUCH_ROTATE:

					if (scope.enableRotate === false) return;

					handleTouchMoveRotate(event);
					scope.update();

					break;

				case STATE.TOUCH_PAN:

					if (scope.enablePan === false) return;

					handleTouchMovePan(event);
					scope.update();

					break;

				case STATE.TOUCH_DOLLY_PAN:

					if (scope.enableZoom === false && scope.enablePan === false) return;

					handleTouchMoveDollyPan(event);
					scope.update();

					break;

				case STATE.TOUCH_DOLLY_ROTATE:

					if (scope.enableZoom === false && scope.enableRotate === false) return;

					handleTouchMoveDollyRotate(event);
					scope.update();

					break;

				default:

					state = STATE.NONE;

			}

		}

		function onTouchEnd(event) {

			if (scope.enabled === false) return;

			handleTouchEnd(event);

			scope.dispatchEvent(endEvent);

			state = STATE.NONE;

		}

		function onContextMenu(event) {

			if (scope.enabled === false) return;

			event.preventDefault();

		}

		//

		scope.domElement.addEventListener('contextmenu', onContextMenu, false);

		scope.domElement.addEventListener('mousedown', onMouseDown, false);
		scope.domElement.addEventListener('wheel', onMouseWheel, false);

		scope.domElement.addEventListener('touchstart', onTouchStart, false);
		scope.domElement.addEventListener('touchend', onTouchEnd, false);
		scope.domElement.addEventListener('touchmove', onTouchMove, false);

		scope.domElement.addEventListener('keydown', onKeyDown, false);

		// make sure element can receive keys.

		if (scope.domElement.tabIndex === -1) {

			scope.domElement.tabIndex = 0;

		}

		// force an update at start

		this.update();

	};

	OrbitControls.prototype = Object.create(EventDispatcher.prototype);
	OrbitControls.prototype.constructor = OrbitControls;


	// This set of controls performs orbiting, dollying (zooming), and panning.
	// Unlike TrackballControls, it maintains the "up" direction object.up (+Y by default).
	// This is very similar to OrbitControls, another set of touch behavior
	//
	//    Orbit - right mouse, or left mouse + ctrl/meta/shiftKey / touch: two-finger rotate
	//    Zoom - middle mouse, or mousewheel / touch: two-finger spread or squish
	//    Pan - left mouse, or arrow keys / touch: one-finger move

	var MapControls = function (object, domElement) {

		OrbitControls.call(this, object, domElement);

		this.mouseButtons.LEFT = MOUSE.PAN;
		this.mouseButtons.RIGHT = MOUSE.ROTATE;

		this.touches.ONE = TOUCH.PAN;
		this.touches.TWO = TOUCH.DOLLY_ROTATE;

	};

	MapControls.prototype = Object.create(EventDispatcher.prototype);
	MapControls.prototype.constructor = MapControls;

	return {
		OrbitControls,
		MapControls
	}
}

export default registerOrbit

三、效果图

四、总结

three.js画一个图形主要经历如下八个步骤：

• 1.创建透视相机
• 2.创建场景
• 3.创建光源
• 4.构造辅助网格
• 5.创建加载器，加载模型文件
• 6.创建渲染器，渲染场景
• 7.创建控制器
• 8.循环渲染场景