[page:LightShadow] →

# [name]

这在SpotLights内部用于计算阴影。

## 代码示例

`//Create a WebGLRenderer and turn on shadows in the renderer const renderer = new THREE.WebGLRenderer(); renderer.shadowMap.enabled = true; renderer.shadowMap.type = THREE.PCFSoftShadowMap; // default THREE.PCFShadowMap //Create a SpotLight and turn on shadows for the light const light = new THREE.SpotLight( 0xffffff ); 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 light.shadow.focus = 1; // default //Create a sphere that cast shadows (but does not receive them) const sphereGeometry = new THREE.SphereGeometry( 5, 32, 32 ); const sphereMaterial = new THREE.MeshStandardMaterial( { color: 0xff0000 } ); const 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) const planeGeometry = new THREE.PlaneGeometry( 20, 20, 32, 32 ); const planeMaterial = new THREE.MeshStandardMaterial( { color: 0x00ff00 } ) const plane = new THREE.Mesh( planeGeometry, planeMaterial ); plane.receiveShadow = true; scene.add( plane ); //Create a helper for the shadow camera (optional) const helper = new THREE.CameraHelper( light.shadow.camera ); scene.add( helper );`

## 构造函数

构造函数创建一个 [param:PerspectiveCamera PerspectiveCamera] 来管理阴影的世界视图

## 属性

有关常用属性，请参阅基础LightShadow类。

### [property:Camera camera]

在光的世界里。这用于生成场景的深度图;从光的角度来看，其他物体背后的物体将处于阴影中。
默认值为PerspectiveCamera，近剪裁平面为0.5。 fov将通过更新方法跟踪拥有SpotLight的角度属性。同样，aspect属性将跟踪mapSize的方面。如果设置了灯光的距离属性，则远剪裁平面将跟踪该值，否则默认为500。

### [property:Number focus]

Used to focus the shadow camera. The camera's field of view is set as a percentage of the spotlight's field-of-view. Range is [0, 1]. Default is 1.0.

### [property:Boolean isSpotLightShadow]

Read-only flag to check if a given object is of type [name].

## 方法

有关常用方法，请参阅基础LightShadow类。

## Source

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