[page:Object3D] → [page:Line] → [page:LineSegments] →

# [name]

用于图形化地展示对象世界轴心对齐的包围盒的辅助对象。The actual bounding box is handled with [page:Box3], this is just a visual helper for debugging. It can be automatically resized with the [page:BoxHelper.update] method when the object it's created from is transformed. 注意:要想能正常运行,目标对象必须包含 [page:Geometry] 或 [page:BufferGeometry] , 所以当目标对象是精灵 [page:Sprite Sprites] 时将不能正常运行.

## 例子

[example:webgl_helpers WebGL / helpers]
[example:webgl_loader_nrrd WebGL / loader / nrrd]
[example:webgl_buffergeometry_drawcalls advanced / buffergeometry / drawcalls]
`var sphere = new THREE.SphereGeometry(); var object = new THREE.Mesh( sphere, new THREE.MeshBasicMaterial( 0xff0000 ) ); var box = new THREE.BoxHelper( object, 0xffff00 ); scene.add( box );`

## 构造函数

### [name]( [param:Object3D object], [param:Color color] )

[page:Object3D object] -- (可选的) 被展示世界轴心对齐的包围盒的对象.
[page:Color color] -- (可选的) 线框盒子的16进制颜色值. 默认为 0xffff00.
创建一个新的线框盒子包围指定的对象. 内部使用 [page:Box3.setFromObject] 方法来计算尺寸. 注意:此线框盒子将包围对象的所有子对象.

## 属性

请到基类 [page:LineSegments] 页面查看公共属性.

## 方法

请到基类 [page:LineSegments] 页面查看公共方法.

### [method:null update]()

更新辅助对象的几何体，与目标对象尺寸 保持一致, 包围目标对象所有子对象. 请查看 [page:Box3.setFromObject].

### [method:BoxHelper setFromObject]( [param:Object3D object] )

[page:Object3D object] - 用于创建辅助对象的目标 [page:Object3D] 对象.
更新指定对象的线框盒子.

## 源码

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