一声登、Camera(基類)
攝像機的抽象基類。在構(gòu)建新攝像機時耸别，應(yīng)始終繼承此類夺饲。這個類并不是被直接調(diào)用的奸汇；你所想要的或許是一個 PerspectiveCamera（透視攝像機）或者 OrthographicCamera（正交攝像機）。
注：繼承自 Object3D
二往声、CubeCamera（立方相機）
構(gòu)造一個包含6個PerspectiveCameras（透視攝像機）的立方攝像機擂找， 并將其拍攝的場景渲染到一個WebGLCubeRenderTarget上。
代碼示例
// Create cube render target
const cubeRenderTarget = new THREE.WebGLCubeRenderTarget( 128, { format: THREE.RGBFormat,
generateMipmaps: true, minFilter: THREE.LinearMipmapLinearFilter } );
// Create cube camera
const cubeCamera = new THREE.CubeCamera(
1,//近剪切面的距離
100000, //遠剪切面的距離
cubeRenderTarget //The destination cube render target
);
scene.add( cubeCamera );
// Create car
const chromeMaterial = new THREE.MeshLambertMaterial( { color: 0xffffff, envMap: cubeRenderTarget.texture } );
const car = new Mesh( carGeometry, chromeMaterial );
scene.add( car );
// Update the render target cube
car.visible = false;
cubeCamera.position.copy( car.position );
cubeCamera.update( renderer, scene );
// Render the scene
car.visible = true;
renderer.render( scene, camera );
