# RoamParticle

#### new Cesium.RoamParticle(viewer, options, positionStart, positionEnd)
MapGIS/PostProcessingEffects/RoamParticle.js 66

跟随模型移动粒子特效

Name | Type | Description
--- | --- | ---
`viewer` | Object | 视图

`options`

Object

附加粒子特效参数

Name | Type | Description
--- | --- | ---
`imageUrl` | String | 粒子url
`modelUrl` | String | 模型url
`minimumPixelSize` | Number | optional 最小像素尺寸

`positionStart` | Cartesian3 | optional 路径起点坐标
`positionEnd` | Cartesian3 | optional 路径终点坐标
`options.viewFrom` | Cartesian3 | optional 观察点
`options.startTime` | Date | optional 开始时间
`options.duration` | Number | optional 持续周期
`options.startColor` | Color | optional 开始的颜色
`options.endColor` | Color | optional 结束的颜色
`options.startScale` | Number | optional 开始的尺寸
`options.endScale` | Number | optional 结束的尺寸
`options.minimumParticleLife` | Number | optional 最小粒子周期
`options.maximumParticleLife` | Number | optional 最大粒子周期
`options.minimumSpeed` | Number | optional 最小速率
`options.maximumSpeed` | Number | optional 最大速率
`options.particleSize` | Number | optional 粒子大小
`options.emissionRate` | Number | optional 排放率
`options.bursts` | Array | optional 爆发形状
`options.lifetime` | Number | optional 单个粒子生命周期
`options.emitter` | object | optional 粒子发射器类型
`options.minimumImageSize` | Number | optional 最小Image尺寸
`options.maximumImageSize` | Number | optional 最大Image尺寸
`options.gravity` | Number | optional 粒子重力

Author:
  - 基础平台研发中心·周凌风

##### Example:

    var options = {
    imageUrl: '../Data/Images/smoke.png',
                  modelUrl: '../CesiumMilkTruck/CesiumMilkTruck.glb',
                 startTime: Cesium.JulianDate.fromDate(new Date(2015, 2, 25, 16)),
                 duration: 120,
                 positionStart: Cesium.Cartesian3.fromDegrees(-75.15787310614596,39.97862668312678),
                 positionEnd: Cesium.Cartesian3.fromDegrees(-75.1633691390455,39.95355089912078)
             };
    roamParticle = new Cesium.RoamParticle(viewer,options);
    roamParticle.start();//开始
    roamParticle.remove();//移除模型与粒子

### Members

#### emissionRate : Number
MapGIS/PostProcessingEffects/RoamParticle.js 243

排放率

#### endColor : Color
MapGIS/PostProcessingEffects/RoamParticle.js 175

结束颜色

#### endScale : Number
MapGIS/PostProcessingEffects/RoamParticle.js 355

结束尺寸

#### gravity : Number
MapGIS/PostProcessingEffects/RoamParticle.js 392

粒子重力

#### image : String
MapGIS/PostProcessingEffects/RoamParticle.js 135

粒子url

#### maximumImageSize : Number
MapGIS/PostProcessingEffects/RoamParticle.js 271

最大Image尺寸

#### maximumParticleLife : Number
MapGIS/PostProcessingEffects/RoamParticle.js 299

最大粒子生命周期

#### maximumSpeed : Number
MapGIS/PostProcessingEffects/RoamParticle.js 327

最大速度

#### minimumImageSize : Number
MapGIS/PostProcessingEffects/RoamParticle.js 257

最小Image尺寸

#### minimumParticleLife : Number
MapGIS/PostProcessingEffects/RoamParticle.js 285

最小粒子生命周期

#### minimumPixelSize : Number
MapGIS/PostProcessingEffects/RoamParticle.js 189

最小像素尺寸

#### minimumSpeed : Number
MapGIS/PostProcessingEffects/RoamParticle.js 313

最小速度

#### modelUrl : String
MapGIS/PostProcessingEffects/RoamParticle.js 148

模型url

#### particleSize : Number
MapGIS/PostProcessingEffects/RoamParticle.js 369

粒子大小

#### particleSystemObject : Object
MapGIS/PostProcessingEffects/RoamParticle.js 382

粒子系统ParticleSystem对象

#### positionEnd : Cartesian3
MapGIS/PostProcessingEffects/RoamParticle.js 213

路径终点坐标

#### positionStart : Cartesian3
MapGIS/PostProcessingEffects/RoamParticle.js 203

路径起点坐标

#### startColor : Color
MapGIS/PostProcessingEffects/RoamParticle.js 161

起始颜色

#### startScale : Number
MapGIS/PostProcessingEffects/RoamParticle.js 341

起始尺寸

#### startTime : Object
MapGIS/PostProcessingEffects/RoamParticle.js 223

起始时间

#### stopTime : Object
MapGIS/PostProcessingEffects/RoamParticle.js 233

结束时间

#### viewer : Object
MapGIS/PostProcessingEffects/RoamParticle.js 125

视图

### Methods

#### remove()
MapGIS/PostProcessingEffects/RoamParticle.js 505

移除

#### start()
MapGIS/PostProcessingEffects/RoamParticle.js 443

开始