Three.js 实现3D场景鼠标滚轮缩放视野

var camera = new THREE.PerspectiveCamera( fov, aspect , near,far );

透视相机初始化与fov动态调整

//透视照相机参数设置
var fov = 45,//拍摄距离 视野角值越大，场景中的物体越小
 near = 1,//相机离视体积最近的距离
 far = 1000,//相机离视体积最远的距离
 aspect = window.innerWidth / window.innerHeight; //纵横比
var camera = new THREE.PerspectiveCamera(fov,aspect, near, far);

//改变fov值，并更新场景的渲染
camera.fov = fov;
camera.updateProjectionMatrix();
renderer.render(scene, camera);
 //updateinfo();

鼠标滚轮事件监听与缩放逻辑实现

//监听鼠标滚动事件
canvas.addEventListener('mousewheel', mousewheel, false);

//鼠标滑轮-鼠标上下滑轮实现放大缩小效果
function mousewheel(e) {
 e.preventDefault();
 //e.stopPropagation();
 if (e.wheelDelta) { //判断浏览器IE，谷歌滑轮事件
 if (e.wheelDelta > 0) { //当滑轮向上滚动时
  fov -= (near < fov ? 1 : 0);
 }
 if (e.wheelDelta < 0) { //当滑轮向下滚动时
  fov += (fov < far ? 1 : 0);
 }
 } else if (e.detail) { //Firefox滑轮事件
 if (e.detail > 0) { //当滑轮向上滚动时
  fov -= 1;
 }
 if (e.detail < 0) { //当滑轮向下滚动时
  fov += 1;
 }
 }
 //改变fov值，并更新场景的渲染
 camera.fov = fov;
 camera.updateProjectionMatrix();
 renderer.render(scene, camera);
 //updateinfo();
}

完整HTML与JavaScript示例代码

<!DOCTYPE html>
<html>
 <head>
 <meta charset="UTF-8">
 <title>threejs中3D视野的缩放</title>
 <style>
 #canvas-frame {
 width: 100%;
 height: 600px;
 }
 </style>
 </head>
 <body onload="threeStart()">
 <div id="canvas-frame" ></div>
 </body>
 <script type="text/javascript" src="./lib/three.js" ></script>
 <script type="text/javascript">
 var renderer, //渲染器
 width = document.getElementById('canvas-frame').clientWidth, //画布宽
 height = document.getElementById('canvas-frame').clientHeight; //画布高
 //照相机配置
 var fov = 45,//拍摄距离 视野角值越大，场景中的物体越小
 near = 1,//最小范围
 far = 1000;//最大范围
 //DOM对象
 var canvas = null;
 //初始化DOM对象 
 function initDOM(){
 canvas = document.getElementById("canvas-frame");
 }
 //初始化渲染器
 function initThree(){
 renderer = new THREE.WebGLRenderer({
  antialias : true
  //canvas: document.getElementById('canvas-frame')
 });
 renderer.setSize(width, height);
 renderer.setClearColor(0xFFFFFF, 1.0);
 document.getElementById('canvas-frame').appendChild(renderer.domElement);
  renderer.setClearColor(0xFFFFFF, 1.0);
 }
 //初始化场景
 var scene;
 function initScene(){
 scene = new THREE.Scene();
 }
 var camera;
 function initCamera() { //透视相机
 camera = new THREE.PerspectiveCamera(fov, width/height , near, far);
 camera.position.x = 150;
 camera.position.y = 150;
 camera.position.z =250;
 camera.up.x = 0;
 camera.up.y = 1; //相机朝向--相机上方为y轴
 camera.up.z = 0;
 camera.lookAt({ //相机的中心点
  x : 0,
  y : 0,
  z : 0
 });
 }
 function initLight(){
 // light--这里使用环境光
 //var light = new THREE.DirectionalLight(0xffffff); /*方向性光源*/
 //light.position.set(600, 1000, 800);
 /* var light = new THREE.AmbientLight(0xffffff); //模拟漫反射光源
 light.position.set(600, 1000, 800); //使用Ambient Light时可以忽略方向和角度，只考虑光源的位置
 scene.add(light);*/
 }
 function initObject(){ //初始化对象
 //初始化地板
 initFloor();
 }
 function initGrid(){ //辅助网格
 var helper = new THREE.GridHelper( 1000, 50 );
 helper.setColors( 0x0000ff, 0x808080 );
 scene.add( helper );
 }
 function initFloor(){
 //创建一个立方体
 var geometry = new THREE.BoxGeometry(80, 20, 80);
  for ( var i = 0; i < geometry.faces.length; i += 2 ) {
  var hex = Math.random() * 0xffffff;
  geometry.faces[ i ].color.setHex( hex );
  geometry.faces[ i + 1 ].color.setHex( hex );
 }
 var material = new THREE.MeshBasicMaterial( { vertexColors: THREE.FaceColors} );
 //将material材料添加到几何体geometry
 var mesh = new THREE.Mesh(geometry, material);
 mesh.position = new THREE.Vector3(0,0,0);
 scene.add(mesh);
 }
 //初始化页面加载
 function threeStart(){
 //初始化DOM对象
 initDOM();
 //初始化渲染器
 initThree();
 //初始化场景
 initScene();
 //初始透视化相机
 initCamera();
 //初始化光源
 initLight();
 //模型对象
 initObject();
 //初始化网格辅助线
 initGrid();
 //渲染
 renderer.render(scene, camera);
 //实时动画
 //animation();
 //监听鼠标滚动事件
 canvas.addEventListener('mousewheel', mousewheel, false);
 }
 function animation(){
 //相机围绕y轴旋转，并且保持场景中的物体一直再相机的视野中
 //实时渲染成像
 var timer = Date.now()*0.0001;
 camera.position.x = Math.cos(timer)*100;
 camera.position.z = Math.sin(timer)*100;
 camera.lookAt(scene.position);
 renderer.render(scene, camera);
 requestAnimationFrame(animation);
 }
 //鼠标滑轮-鼠标上下滑轮实现放大缩小效果
 function mousewheel(e) {
 e.preventDefault();
 //e.stopPropagation();
 if (e.wheelDelta) { //判断浏览器IE，谷歌滑轮事件
 if (e.wheelDelta > 0) { //当滑轮向上滚动时
  fov -= (near < fov ? 1 : 0);
 }
 if (e.wheelDelta < 0) { //当滑轮向下滚动时
  fov += (fov < far ? 1 : 0);
 }
 } else if (e.detail) { //Firefox滑轮事件
 if (e.detail > 0) { //当滑轮向上滚动时
  fov -= 1;
 }
 if (e.detail < 0) { //当滑轮向下滚动时
  fov += 1;
 }
 }
 console.info('camera.fov:'+camera.fov);
 console.info('camera.x:'+camera.position.x);
 console.info('camera.y:'+camera.position.y);
 console.info('camera.z:'+camera.position.z);
 //改变fov值，并更新场景的渲染
 camera.fov = fov;
 camera.updateProjectionMatrix();
 renderer.render(scene, camera);
 //updateinfo();
 }
 </script>
</html>