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threejs--自定义矩阵实现全景视觉

threejs--自定义矩阵实现全景视觉

作者: 花拾superzay | 来源:发表于2020-08-21 13:34 被阅读0次

本文需要你有基础的webgl知识,了解矩阵、向量、透视投影、裁剪空间、视图变换和threejs框架等等内容。

在线查看地址,手机或pc浏览器访问:http://47.110.129.207/threejs/vr.html

详细代码参考如下

<!DOCTYPE html>
<html>

  <head>
    <title>threejs-全景</title>
    <meta http-equiv="content-type" content="text/html;charset=UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=2,maximum-scale=1,user-scalable=yes">
    <meta http-equiv="X-UA-Compatible"  content="IE=edge,chrome=1"  />

    <style>
      html,
      body {
        padding: 0;
        margin: 0;
        overflow: hidden;
      }
      
      canvas {
        width: 100%;
        height: 100%
      }
    </style>
  </head>

  <body>
    <script src="https://cdn.bootcdn.net/ajax/libs/three.js/100/three.min.js"></script>
    <script>
      // 创建渲染器
      var renderer = new THREE.WebGLRenderer();
      renderer.setSize(window.innerWidth, window.innerHeight) // 设置画布大小
      document.body.appendChild(renderer.domElement); //插入dom树

      // 创建场景
      var scene = new THREE.Scene();

      // 创建相机
      var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
      camera.position.set(0, -0, 0) // 设置相机位置
      camera.lookPoint = {} // 观察点
      camera.lookPoint.x = 0
      camera.lookPoint.y = 0
      camera.lookPoint.z = -1
      camera.lookAt(camera.lookPoint.x, camera.lookPoint.y, camera.lookPoint.z)

      // 几何体、材质、模型、立方体纹理
      var textureLoader = new THREE.CubeTextureLoader().setPath('http://47.110.129.207/images/vr/'); // 立方纹理      
      var arr = ['x1.jpg', 'x2.jpg', 'y2.jpg', 'y1.jpg', 'z2.jpg', 'z1.jpg'] // 6张纹理图依次贴在立方体的x正、x负、y负、y正、z负、z正6个面
      var texture = textureLoader.load(arr);
      var geometry = new THREE.BoxGeometry(50, 50, 50); // 几何体
      var material = new THREE.MeshPhongMaterial({
        envMap: texture,
        side: THREE.DoubleSide
      });
      var cube = new THREE.Mesh(geometry, material); // 创建mesh
      cube.position.set(-0, -0, -0)
      scene.add(cube) // 加入场景

      //环境光
      let ambient = new THREE.AmbientLight(0xffffff);
      scene.add(ambient)

      // 渲染
      function render() {
        renderer.render(scene, camera);
        requestAnimationFrame(render)
      }
      render();

      // vr全景
      (function() {

        // 触点初始坐标
        let initPos = {
          x: null,
          y: null,
        }

        let open = false // 开启
        let coe = 0.2 // 系数
        let matrixWorldInverse = null // 初始视图矩阵
        let matrixWorld = null // 初始视图矩阵的逆矩阵

        // 初始观察点        
        let lookPoint = {
          x: null,
          y: null,
          z: null
        }

        // 初始上方向向量 
        let up = {
          x: null,
          y: null,
          z: null
        }

        let touchId = null // 触点id

        // 判断浏览器环境
        if(navigator.userAgent.match(/android|iphone|symbianos|window\sphone|ipad|ipos/gi) === null) {
          // pc
          // 开启
          renderer.domElement.addEventListener('mousedown', function(event) {
            event = event || window.event

            // 触点水平和垂直坐标
            let x = event.clientX - renderer.domElement.getBoundingClientRect().left
            let y = event.clientY - renderer.domElement.getBoundingClientRect().top

            // 记录初始状态
            initPos.x = x
            initPos.y = y
            open = true
            matrixWorld = camera.matrixWorld.clone()
            matrixWorldInverse = camera.matrixWorldInverse.clone()
            lookPoint.x = camera.lookPoint.x
            lookPoint.y = camera.lookPoint.y
            lookPoint.z = camera.lookPoint.z
            up.x = camera.up.x
            up.y = camera.up.y
            up.z = camera.up.z

          })

          // 查看
          renderer.domElement.addEventListener('mousemove', function(event) {
            if(!open) return
            event = event || window.event

            // 触点水平和垂直坐标
            let x = event.clientX - renderer.domElement.getBoundingClientRect().left
            let y = event.clientY - renderer.domElement.getBoundingClientRect().top

            let diffX = x - initPos.x // 移动距离
            let diffY = y - initPos.y

            // 转角度
            let angleX = Math.PI / 180 * diffX * coe
            let angleY = Math.PI / 180 * diffY * coe

            // x轴旋转矩阵
            let xRotateMatrix = new THREE.Matrix4().set(1, 0, 0, 0, 0, Math.cos(angleY), -Math.sin(angleY), 0, 0, Math.sin(angleY), Math.cos(angleY), 0, 0, 0, 0, 1)

            // y轴旋转矩阵
            let yRotateMatrix = new THREE.Matrix4().set(Math.cos(angleX), 0, Math.sin(angleX), 0, 0, 1, 0, 0, -Math.sin(angleX), 0, Math.cos(angleX), 0, 0, 0, 0, 1)

            // 计算观察点的旋转
            let lookPointVector = new THREE.Vector4(lookPoint.x, lookPoint.y, lookPoint.z, 1).applyMatrix4(matrixWorldInverse).applyMatrix4(xRotateMatrix).applyMatrix4(yRotateMatrix).applyMatrix4(matrixWorld)

            // 计算上方向向量的旋转
            let upStartVector = new THREE.Vector4(0, 0, 0, 1).applyMatrix4(matrixWorldInverse).applyMatrix4(xRotateMatrix).applyMatrix4(yRotateMatrix).applyMatrix4(matrixWorld)
            let upEndVector = new THREE.Vector4(up.x, up.y, up.z, 1).applyMatrix4(matrixWorldInverse).applyMatrix4(xRotateMatrix).applyMatrix4(yRotateMatrix).applyMatrix4(matrixWorld)

            // 更新相机
            camera.up.set(upEndVector.x - upStartVector.x, upEndVector.y - upStartVector.y, upEndVector.z - upStartVector.z)
            camera.lookPoint.x = lookPointVector.x
            camera.lookPoint.y = lookPointVector.y
            camera.lookPoint.z = lookPointVector.z
            camera.lookAt(camera.lookPoint.x, camera.lookPoint.y, camera.lookPoint.z)

          })

          // 监听结束
          window.addEventListener('mouseup', overLook)
          window.addEventListener('mouseout', overLook)

          // 结束查看函数
          function overLook(event) {
            open = false
            matrixWorldInverse = null
            matrixWorld = null
            lookPoint = {
              x: null,
              y: null,
              z: null
            }
            up = {
              x: null,
              y: null,
              z: null
            }
            touchId = null

          }

        } else {
          // 移动
          // 开启
          renderer.domElement.addEventListener('touchstart', function(event) {
            event = event || window.event

          
            if(event.touches.length > 1) {
              overTurn(event)
              return
            }

            // 触点水平和垂直坐标
            let x = event.touches[0].clientX - renderer.domElement.getBoundingClientRect().left
            let y = event.touches[0].clientY - renderer.domElement.getBoundingClientRect().top

            // 记录初始状态
            initPos.x = x
            initPos.y = y
            open = true
            matrixWorld = camera.matrixWorld.clone() 
            matrixWorldInverse = camera.matrixWorldInverse.clone() 
            lookPoint.x = camera.lookPoint.x 
            lookPoint.y = camera.lookPoint.y 
            lookPoint.z = camera.lookPoint.z 
            up.x = camera.up.x 
            up.y = camera.up.y 
            up.z = camera.up.z 
            touchId = event.touches[0].identifier

          })

          //查看
          renderer.domElement.addEventListener('touchmove', function(event) {
            if(!open) return 
            event = event || window.event
            event.preventDefault()

            // 查找初始点
            let touch
            for(let i = 0; i < event.touches.length; i++) {
              if(event.touches[i].identifier === touchId) {
                touch = event.touches[i]
              }
            }
            if(!touch) return

            // 触点的水平和垂直坐标
            let x = touch.clientX - renderer.domElement.getBoundingClientRect().left
            let y = touch.clientY - renderer.domElement.getBoundingClientRect().top

            let diffX = x - initPos.x // 移动距离
            let diffY = y - initPos.y 

            // 转角度
            let angleX = Math.PI / 180 * diffX * coe
            let angleY = Math.PI / 180 * diffY * coe

            // x轴旋转矩阵
            let xRotateMatrix = new THREE.Matrix4().set(1, 0, 0, 0, 0, Math.cos(angleY), -Math.sin(angleY), 0, 0, Math.sin(angleY), Math.cos(angleY), 0, 0, 0, 0, 1)
            // y轴旋转矩阵
            let yRotateMatrix = new THREE.Matrix4().set(Math.cos(angleX), 0, Math.sin(angleX), 0, 0, 1, 0, 0, -Math.sin(angleX), 0, Math.cos(angleX), 0, 0, 0, 0, 1)

            // 计算观察点旋转
            let lookPointVector = new THREE.Vector4(lookPoint.x, lookPoint.y, lookPoint.z, 1).applyMatrix4(matrixWorldInverse).applyMatrix4(xRotateMatrix).applyMatrix4(yRotateMatrix).applyMatrix4(matrixWorld)

            // 计算上方向向量旋转
            let upStartVector = new THREE.Vector4(0, 0, 0, 1).applyMatrix4(matrixWorldInverse).applyMatrix4(xRotateMatrix).applyMatrix4(yRotateMatrix).applyMatrix4(matrixWorld)
            let upEndVector = new THREE.Vector4(up.x, up.y, up.z, 1).applyMatrix4(matrixWorldInverse).applyMatrix4(xRotateMatrix).applyMatrix4(yRotateMatrix).applyMatrix4(matrixWorld)

            // 更新相机
            camera.up.set(upEndVector.x - upStartVector.x, upEndVector.y - upStartVector.y, upEndVector.z - upStartVector.z)
            camera.lookPoint.x = lookPointVector.x
            camera.lookPoint.y = lookPointVector.y
            camera.lookPoint.z = lookPointVector.z
            camera.lookAt(camera.lookPoint.x, camera.lookPoint.y, camera.lookPoint.z)

          }, {
            passive: false
          })

          // 监听结束
          window.addEventListener('touchend', overLook1)
          window.addEventListener('touchcancel', overLook1)

          // 结束查看函数
          function overLook1(event) {
            // 结束拖拽,数据初始化
            open = false
            matrixWorldInverse = null
            matrixWorld = null
            lookPoint = {
              x: null,
              y: null,
              z: null
            }
            up = {
              x: null,
              y: null,
              z: null
            }
            touchId = null
          }

        }

      })()
    </script>
  </body>

</html>

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