# [name]

该类在内部由[page:PointLight PointLights]所使用，以用于计算阴影。

## 示例

`//Create a WebGLRenderer and turn on shadows in the renderer var renderer = new THREE.WebGLRenderer(); renderer.shadowMap.enabled = true; renderer.shadowMap.type = THREE.PCFSoftShadowMap; // default THREE.PCFShadowMap //Create a PointLight and turn on shadows for the light var light = new THREE.PointLight( 0xffffff, 1, 100 ); light.position.set( 0, 10, 0 ); light.castShadow = true; // default false scene.add( light ); //Set up shadow properties for the light light.shadow.mapSize.width = 512; // default light.shadow.mapSize.height = 512; // default light.shadow.camera.near = 0.5; // default light.shadow.camera.far = 500 // default //Create a sphere that cast shadows (but does not receive them) var sphereGeometry = new THREE.SphereBufferGeometry( 5, 32, 32 ); var sphereMaterial = new THREE.MeshStandardMaterial( { color: 0xff0000 } ); var sphere = new THREE.Mesh( sphereGeometry, sphereMaterial ); sphere.castShadow = true; //default is false sphere.receiveShadow = false; //default scene.add( sphere ); //Create a plane that receives shadows (but does not cast them) var planeGeometry = new THREE.PlaneBufferGeometry( 20, 20, 32, 32 ); var planeMaterial = new THREE.MeshStandardMaterial( { color: 0x00ff00 } ) var plane = new THREE.Mesh( planeGeometry, planeMaterial ); plane.receiveShadow = true; scene.add( plane ); //Create a helper for the shadow camera (optional) var helper = new THREE.CameraHelper( light.shadow.camera ); scene.add( helper );`

## 构造函数

### [name]( )

创建一个新的[name]。该方法不是直接调用的 —— 其在内部由[page:PointLight]调用。

## 属性

共有属性请参见其基类[page:LightShadow LightShadow]。

## 方法

### [method:null updateMatrices]( [param:Light light], [param:number viewportIndex])

Update the matrices for the camera and shadow, used internally by the renderer.
light -- the light for which the shadow is being rendered.
viewportIndex -- calculates the matrix for this viewport

共有方法请参见其基类[page:LightShadow LightShadow]。

## 源代码

[link:https://github.com/mrdoob/three.js/blob/master/src/lights/[name].js src/lights/[name].js]