# SampleElevationTool

#### new Cesium.SampleElevationTool(viewer, positions, type, callBackFuntion)
MapGIS/Tools/SampleElevationTool.js 23

采样高程工具，从地形或模型上采样真实高程，返回结果为角度制的经纬度坐标

Name | Type | Description
--- | --- | ---
`viewer` | Object | 场景视图对象
`positions` | Array | 坐标数组,世界坐标Cartesian3
`type` | String | 数据类型，m3d模型缓存：'model'，地形：'terrain',通用：'general'
`callBackFuntion` | function | 用于返回结果的回调函数，参数result为结果，使用经纬度坐标Cartographic的数组进行存储

Author:
  - zlf

##### Example:

    function callBackFuntion(result){
        var elevationPosition = result;
    }
    var tool = new Cesium.SampleElevationTool(viewer,positions,'model',callBackFuntion);
    tool.start();

### Methods

#### start(options)
MapGIS/Tools/SampleElevationTool.js 37

采样高程

Name | Type | Description
--- | --- | ---
`options` | Object |
Name | Type | Description
--- | --- | ---
`level` | Number | optional 采样精度，暂时仅支持地形采样精度设置