Three.js - 正交攝像機

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第二種最常見的攝像機是正交攝像機。它指定一個包含以下設定的盒子：左、右、上、下、近和遠。它用二維形式表示三維物體。

const camera = new THREE.OrthographicCamera(left, right, top, bottom, near, far)

所有這六個屬性都是盒子的邊框；攝像機只渲染盒子內的物體。

  • 左 - 攝像機的左邊平面。

  • 右 - 攝像機的右邊平面。

  • 上 - 攝像機の上邊平面。

  • 下 - 攝像機的下邊平面。

  • 近 - 攝像機的近平面。

  • 遠 - 攝像機的遠平面。

Camera Angles

示例

檢視以下示例 −

orthographic-cam.html

<!DOCTYPE html>
<html lang="en">
   <head>
      <meta charset="UTF-8" />
      <meta http-equiv="X-UA-Compatible" content="ie=edge" />
      <meta name="viewport" content="width=device-width, initial-scale=1.0" />
      <title>Three.js - Orthographic camera</title>
         <style>
         html,
         body {
            margin: 0;
            height: 100%;
         }
         #threejs-container {
            width: 100%;
            height: 100%;
            display: block;
         }
         .split {
            position: absolute;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            display: flex;
         }
         .split > div {
            width: 100%;
            height: 100%;
         }
      </style>
      <script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
      <script src="https://cdnjs.cloudflare.com/ajax/libs/dat-gui/0.7.7/dat.gui.js"></script>
   </head>
   <body>
      <canvas id="threejs-container"></canvas>
      <div class="split">
         <div id="view1" tabindex="1"></div>
         <div id="view2" tabindex="2"></div>
      </div>
      <script type="module">
         // Three.js - Cameras - Orthographic 2 views
         // from https://threejsfundamentals.org/threejs/threejs-camerasorthographic-2-scenes.html
         import { OrbitControls } from "https://threejs.org/examples/jsm/contro
         ls/OrbitControls.js"
         function main() {
            const canvas = document.querySelector('#threejs-container')
            const view1Elem = document.querySelector('#view1')
            const view2Elem = document.querySelector('#view2')
            const renderer = new THREE.WebGLRenderer({ canvas, antialias: true })
            const size = 1
            const near = 5
            const far = 50
            const camera = new THREE.OrthographicCamera(-size, size, size, -
            size, near, far)
            camera.zoom = 0.2
            camera.position.set(0, 10, 20)
            const cameraHelper = new THREE.CameraHelper(camera)
            class MinMaxGUIHelper {
               constructor(obj, minProp, maxProp, minDif) {
                  this.obj = obj
                  this.minProp = minProp
                  this.maxProp = maxProp
                  this.minDif = minDif
               }
               get min() {
                  return this.obj[this.minProp]
               }
               set min(v) {
                  this.obj[this.minProp] = v
                  this.obj[this.maxProp] = Math.max(this.obj[this.maxProp], v + th
                  is.minDif)
               }
               get max() {
                  return this.obj[this.maxProp]
               }
               set max(v) {
                  this.obj[this.maxProp] = v
                  this.min = this.min // this will call the min setter
               }
            }
            const gui = new dat.GUI()
            gui.add(camera, 'zoom', 0.01, 1, 0.01).listen()
            const minMaxGUIHelper = new MinMaxGUIHelper(camera, 'near', 'far', 0.1)
            gui.add(minMaxGUIHelper, 'min', 0.1, 50, 0.1).name('near')
            gui.add(minMaxGUIHelper, 'max', 0.1, 50, 0.1).name('far')
            const controls = new OrbitControls(camera, view1Elem)
            controls.target.set(0, 5, 0)
            controls.update()
            const camera2 = new THREE.PerspectiveCamera(
               60, // fov
               2, // aspect
               0.1, // near
               500 // far
            )
            camera2.position.set(16, 28, 40)
            camera2.lookAt(0, 5, 0)
            const controls2 = new OrbitControls(camera2, view2Elem)
            controls2.target.set(0, 5, 0)
            controls2.update()
            const scene = new THREE.Scene()
            scene.background = new THREE.Color(0x262626)
            scene.add(cameraHelper)
            {
               const planeSize = 40
               const planeGeo = new THREE.PlaneGeometry(planeSize, planeSize)
               const planeMat = new THREE.MeshLambertMaterial({
                  color: 0xffffff,
                  side: THREE.DoubleSide
               })
               const mesh = new THREE.Mesh(planeGeo, planeMat)
               mesh.rotation.x = Math.PI * -0.5
               scene.add(mesh)
            }
            {
               const cubeSize = 4
               const cubeGeo = new THREE.BoxGeometry(cubeSize, cubeSize, cubeSize)
               const cubeMat = new THREE.MeshPhongMaterial({ color: 0x87ceeb })
               const mesh = new THREE.Mesh(cubeGeo, cubeMat)
               mesh.position.set(cubeSize + 1, cubeSize / 2, 0)
               scene.add(mesh)
            }
            {
               const sphereRadius = 3
               const sphereWidthDivisions = 32
               const sphereHeightDivisions = 16
               const sphereGeo = new THREE.SphereGeometry(
                  sphereRadius,
                  sphereWidthDivisions,
                  sphereHeightDivisions
               )
               const sphereMat = new THREE.MeshPhongMaterial({ color: 0x71ba80 })
               const mesh = new THREE.Mesh(sphereGeo, sphereMat)
               mesh.position.set(-sphereRadius - 1, sphereRadius + 2, 0)
               scene.add(mesh)
            }
            {
               const color = 0xffffff
               const intensity = 1
               const light = new THREE.DirectionalLight(color, intensity)
               light.position.set(0, 10, 5)
               light.target.position.set(-5, 0, 0)
               scene.add(light)
               scene.add(light.target)
               const light2 = new THREE.DirectionalLight(color, intensity)
               light2.position.set(0, 10, -5)
               light2.target.position.set(-5, 0, 0)
               scene.add(light2)
               scene.add(light2.target)
            }
            function resizeRendererToDisplaySize(renderer) {
               const canvas = renderer.domElement
               const width = canvas.clientWidth
               const height = canvas.clientHeight
               const needResize = canvas.width !== width || canvas.height !== height
               if (needResize) {
                  renderer.setSize(width, height, false)
               }
               return needResize
            }
            function setScissorForElement(elem) {
               const canvasRect = canvas.getBoundingClientRect()
               const elemRect = elem.getBoundingClientRect()
               // compute a canvas relative rectangle
               const right = Math.min(elemRect.right, canvasRect.right) - canvasR
               ect.left
               const left = Math.max(0, elemRect.left - canvasRect.left)
               const bottom = Math.min(elemRect.bottom, canvasRect.bottom) - canv
               asRect.top
               const top = Math.max(0, elemRect.top - canvasRect.top)
               const width = Math.min(canvasRect.width, right - left)
               const height = Math.min(canvasRect.height, bottom - top)
               // setup the scissor to only render to that part of the canvas
               const positiveYUpBottom = canvasRect.height - bottom
               renderer.setScissor(left, positiveYUpBottom, width, height)
               renderer.setViewport(left, positiveYUpBottom, width, height)
               // return the aspect
               return width / height
            }
            function render() {
               resizeRendererToDisplaySize(renderer)
               // turn on the scissor
               renderer.setScissorTest(true)
               // render the original view
               {
                  const aspect = setScissorForElement(view1Elem)
                  // update the camera for this aspect
                  camera.left = -aspect
                  camera.right = aspect
                  camera.updateProjectionMatrix()
                  cameraHelper.update()
                  // don't draw the camera helper in the original view
                  cameraHelper.visible = false
                  scene.background.set(0x262626)
                  renderer.render(scene, camera)
               }
               // render from the 2nd camera
               {
                  const aspect = setScissorForElement(view2Elem)
                  // update the camera for this aspect
                  camera2.aspect = aspect
                  camera2.updateProjectionMatrix()
                  // draw the camera helper in the 2nd view
                  cameraHelper.visible = true
                  scene.background.set(0x262626)
                  renderer.render(scene, camera2)
               }
               requestAnimationFrame(render)
            }
            requestAnimationFrame(render)
         }
         main()
      </script>
   </body>
</html>

輸出

Camera Position
threejs_cameras.htm
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