编辑器:webstorm
服务:node.js npm
CesiumJS: Cesium-v1.9.1
vue: v 2.9.6
功能
点击地图标点并显示数字,两点之间连线测距,距离显示在线段正中,三点以上连成面,面积显示在围成面积的最后一点的斜上方。
主界面
画线测距
点击“标点测距”按钮,鼠标移动到地图上,单击左键标点,同时点上出现标号。鼠标移动时对应的点跟着动态移动。有多少点标记多少号,线段中点显示两点间距离,单位为km。
(如果想每条线的起点标号都以1开始需要在draw(type)
里let pointNum = this.pointNum
,然后Ctrl
+F
查找每个that.pointNum
,将that
删掉)
画面测面积
点击“标点测面”按钮,鼠标移动到地图上,单击左键标点,同时点上出现标号。鼠标移动时对应的点跟着动态移动。有多少点标记多少号,围成面积的最后一点的斜上方显示面积,单位为平方公里。
思路
官方示例
- Callback Property - 计算线段长度 文字居中
- Billboards + Points - 往地图上加点
- Labels + Map Pins + Picking - 往地球上加标签
- Polyline - 连线
- Polyline Dash + Polygon - 画面
界面构成
- 初始化镜头 还是设定为火山口
- 显示提示界面
- 提示界面中含有测距、测量面积、清空绘制三个按钮
按钮功能
- 选择测距,点击地图,出现点并显示标号,两点间以线连接,线端中间显示距离,点击右键结束测量
- 选择测量面积,点击地图,出现点并显示标号,两点间以线连接,三点及以上成面,围成的面积的具体数据显示在中心,点击右键结束测量
- 选择全部测量,点击地图,显示两点间距离以及围成的面的面积信息,点击右键结束测量
- 选择清空绘制,地图上的标记全部消失
功能实现
标点显示序号
参考同文集下基于Cesium绘制点线面文件
要在点上方显示序号 -> Cesium的label功能 规定文字 大小
点和序号同时显示 -> 添加的实体里同时包含point和label
数字为点的序号 -> 将包含位置信息的数组的长度传进方法里 -> 在原方法的基础上修改一下,要新增一个参数作为label的text的值
两点中间显示距离
Cesium.Cartographic.fromCartesian (cartesian, ellipsoid , result )
-> 从笛卡尔位置创建一个新的制图实例
new Cesium.EllipsoidGeodesic ( start , end , ellipsoid )
-> 在连接两个提供的行星点的椭球上初始化一个测地线。
-
setEndPoints (start, end)
-> 设置测地线的起点和终点 -
surfaceDistance
-> 获取起点和终点之间的表面距离
问题
-
报错value.replace is not a function
-
问题描述:vue中添加方法drawPointLabel (position, pointNum),希望单击鼠标左键在地图上标点同时出现序号
引用时代码为
let point = that.drawPointLabel(tempPoints[tempPoints.length - 1], tempPoints.length)
,报错value.replace is not a function -
问题分析:方法drawPointLabel具体代码:
drawPointLabel (position, pointNum) { let viewer = this.viewer // 本质上就是添加一个点的实体 return viewer.entities.add({ name: '点几何对象', position: position, point: { color: Cesium.Color.WHEAT, pixelSize: 5, outlineWidth: 3, disableDepthTestDistance: Number.POSITIVE_INFINITY, heightReference: Cesium.HeightReference.CLAMP_TO_GROUND // 规定贴地 }, label: { text: pointNum, font: '30px sans-serif', fillColor: Cesium.Color.WHITE, outlineWidth: 2, backgroundColor: Cesium.Color.BLACK, showBackground: true, style: Cesium.LabelStyle.FILL, verticalOrigin: Cesium.VerticalOrigin.BOTTOM, horizontalOrigin: Cesium.HorizontalOrigin.CENTER } }) }
其中label的text属性需求的数据类型为字符串,但起初传给它的pointNum的数据类型是number,并不匹配
解决办法:用JSON.stingify方法转换数据为字符串,即将调用代码改为
let point = that.drawPointLabel(tempPoints[tempPoints.length - 1], JSON.stringify(tempPoints.length))
-
世界坐标、地表坐标区别
-
计算面积函数返回NaN,对参数使用
JSON.stringify
方法后返回null问题分析:已知getArea方法返回值出错,方法中使用了自己写的getLength,pointAngle,Bearing方法,则需要排查这些方法返回值的类型并将相应返回值修改为number型,再通过
JSON.stringify
转换为可被label的text识别的字符串问题排查:getLength没问题,getArea调用pointAngle, pointAngle调用Bearing。这一部分借鉴的是网上代码,稀奇古怪,没看明白。但是看明白了最后Math.sin()里不应该是角度值而是弧度值,搞不清之前角度转弧度然后再转角度是在干嘛,自己改成了直接用
Cesium.Cartographic.fromCartesian
转弧度。然后好像就没问题了。解决办法(改后代码):
// 方向 Bearing (from, to) { let fromCartographic = Cesium.Cartographic.fromCartesian(from) let toCartographic = Cesium.Cartographic.fromCartesian(to) let lat1 = fromCartographic.latitude let lon1 = fromCartographic.longitude let lat2 = toCartographic.latitude let lon2 = toCartographic.longitude let angle = -Math.atan2(Math.sin(lon1 - lon2) * Math.cos(lat2), Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2)) if (angle < 0) { angle += Math.PI * 2.0 } return angle }, // 角度 pointAngle (point1, point2, point3) { let bearing21 = this.Bearing(point2, point1) let bearing23 = this.Bearing(point2, point3) let angle = bearing21 - bearing23 if (angle < 0) { angle += Math.PI * 2.0 } return angle }
另外getArea返回的时候自己加了
返回值.toFixed(2)
,但是用了这个方法以后就变成了string类型,不符合后来用的math.abs()
的number参数类型,所以在中间又用parseFloat
转了一道,同样的也可以先Math.abs()
再toFixed(2)
,这样其实更高效,后续也不用再JSON.stringify
转成字符串了解决办法一:
getArea (positions) { let res = 0 for (let i = 0; i < positions.length - 2; i++) { let j = (i + 1) % positions.length let k = (i + 2) % positions.length let totalAngle = this.pointAngle(positions[i], positions[j], positions[k]) let tempLength1 = this.getLength(positions[j], positions[0]) let tempLength2 = this.getLength(positions[k], positions[0]) res += tempLength1 * tempLength2 * Math.sin(totalAngle) / 2 } res = res.toFixed(2) // console.log(res) res = parseFloat(res) // console.log(Math.abs(res)) return Math.abs(res) }
解决办法二:
getArea (positions) { let res = 0 for (let i = 0; i < positions.length - 2; i++) { let j = (i + 1) % positions.length let k = (i + 2) % positions.length let totalAngle = this.pointAngle(positions[i], positions[j], positions[k]) let tempLength1 = this.getLength(positions[j], positions[0]) let tempLength2 = this.getLength(positions[k], positions[0]) res += tempLength1 * tempLength2 * Math.sin(totalAngle) / 2 } res = Math.abs(res)res.toFixed(2) return res.toFixed(2) }
然后将调用该方法的对应代码从
that.addArea(JSON.stringify(pointArea), tempPoints)
改成
that.addArea(pointArea, tempPoints)
具体代码
总代码
配置部分见同文集下环境搭建
<template>
<div id="app">
<div id="cesiumContainer"></div>
<div class="btnContainer">
<button @click="draw('Polyline')">标点测距</button>
<button @click="draw('Polygon')">标点测面</button>
<button @click="clearAllDrawn()">清空数据</button>
<div class="tip">
<p>点击按钮后,在场景内单击左键标点,单击右键结束测量。</p>
<p>点击“标点测距”按钮后在场景内单击鼠标左键加点,在两点间显示距离,单击右键结束测量。</p>
<p>点击“标点测面”按钮后在场景内单击鼠标左键加点,单击右键在勾出的范围中显示面积。</p>
<p>点击“清空数据”按钮删除所有数据。</p>
<p>剩下的我慢慢写</p>
</div>
</div>
</div>
</template>
<script>
import * as Cesium from 'cesium/Cesium'
import * as widgets from 'cesium/Widgets/widgets.css'
export default {
name: 'App',
data () {
return {
viewer: undefined,
tempEntities: [],
pointNum: 0,
floatingPoint: undefined,
activeShape: undefined
}
},
mounted () {
this.Init()
},
methods: {
/* 初始化 */
Init () {
// 引入个人token
Cesium.Ion.defaultAccessToken = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiJkYmJkNWQ3Mi0zOGVkLTQ5N2YtYTBmMy0wMDAyODZiMDMyZWYiLCJpZCI6ODQ2NzQsImlhdCI6MTY0NjQ0NTYxNX0.XkHX3rdysM4uUe5VTKDVEV3W2An33zyh4qAkFUac2fk'
// 设置取景器
this.viewer = new Cesium.Viewer('cesiumContainer', {
terrainProvider: Cesium.createWorldTerrain(),
selectionIndicator: false, // 不显示指示器小部件
infoBox: false, // 不显示信息框
sceneModePicker: false, // 不显示模式切换选项
baseLayerPicker: false,
navigationHelpButton: false,
animation: false,
shouldAnimate: false,
timeline: false,
geocoder: false,
homeButton: false,
// 添加ArcGIS在线影像底图
imageryProvider: new Cesium.UrlTemplateImageryProvider({
url: 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}',
subdomains: ['0', '1', '2', '3'],
tilingScheme: new Cesium.WebMercatorTilingScheme()
})
})
// 若浏览器不支持pickPosition,显示报错信息
if (!this.viewer.scene.pickPositionSupported) {
window.alert('This browser does not support pickPosition.')
}
// 载入OSM建筑物
// const osmBuildings = this.viewer.scene.primitives.add(Cesium.createOsmBuildings()) // eslint-disable-line no-unused-vars
// 初始化镜头
this.viewer.camera.lookAt(
Cesium.Cartesian3.fromDegrees(-122.2058, 46.1955, 1000.0),
new Cesium.Cartesian3(5000.0, 5000.0, 5000.0)
)
this.viewer.camera.lookAtTransform(Cesium.Matrix4.IDENTITY)
},
/* 空间两点距离计算函数 */
getLength (start, end) {
// 将起点与终点位置信息从笛卡尔坐标形式转换为Cartographic形式
let startCartographic = Cesium.Cartographic.fromCartesian(start)
let endCartographic = Cesium.Cartographic.fromCartesian(end)
// 初始化测地线
let geodesic = new Cesium.EllipsoidGeodesic()
// 设置测地线起点和终点,EllipsoidGeodesic中setEndPoints常与surfaceDistance搭配使用
geodesic.setEndPoints(startCartographic, endCartographic)
// 获取起点和终点之间的表面距离,单位为km,规定四舍五入保留两位小数
// surfaceDistance返回number 单位为m,带小数
// console.log((geodesic.surfaceDistance / 1000).toFixed(2))
return (geodesic.surfaceDistance / 1000).toFixed(2)
},
/* 空间两点计算中点函数 */
getMidpoint (start, end) {
let startPoint = Cesium.Cartographic.fromCartesian(start)
let endPoint = Cesium.Cartographic.fromCartesian(end)
let geodesic = new Cesium.EllipsoidGeodesic()
geodesic.setEndPoints(startPoint, endPoint)
let geoPoint = geodesic.interpolateUsingFraction(0.5)
console.log(Cesium.Ellipsoid.WGS84.cartographicToCartesian(geoPoint))
return Cesium.Ellipsoid.WGS84.cartographicToCartesian(geoPoint)
},
addLabel (midPoint, labelLength) {
let viewer = this.viewer
return viewer.entities.add({
name: '中点',
position: midPoint,
label: {
text: labelLength + 'km',
font: '20px sans-serif',
fillColor: Cesium.Color.WHITE,
outlineWidth: 2,
backgroundColor: Cesium.Color.BLACK,
showBackground: true,
style: Cesium.LabelStyle.FILL,
verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
horizontalOrigin: Cesium.HorizontalOrigin.CENTER,
heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
disableDepthTestDistance: Number.POSITIVE_INFINITY
}
})
},
/* 测量空间面积 */
// 方向
Bearing (from, to) {
let fromCartographic = Cesium.Cartographic.fromCartesian(from)
let toCartographic = Cesium.Cartographic.fromCartesian(to)
let lat1 = fromCartographic.latitude
let lon1 = fromCartographic.longitude
let lat2 = toCartographic.latitude
let lon2 = toCartographic.longitude
let angle = -Math.atan2(Math.sin(lon1 - lon2) * Math.cos(lat2), Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2))
if (angle < 0) {
angle += Math.PI * 2.0
}
return angle
},
// 角度
pointAngle (point1, point2, point3) {
let bearing21 = this.Bearing(point2, point1)
let bearing23 = this.Bearing(point2, point3)
let angle = bearing21 - bearing23
if (angle < 0) {
angle += Math.PI * 2.0
}
return angle
},
getArea (positions) {
let res = 0
for (let i = 0; i < positions.length - 2; i++) {
let j = (i + 1) % positions.length
let k = (i + 2) % positions.length
let totalAngle = this.pointAngle(positions[i], positions[j], positions[k])
let tempLength1 = this.getLength(positions[j], positions[0])
let tempLength2 = this.getLength(positions[k], positions[0])
res += tempLength1 * tempLength2 * Math.sin(totalAngle) / 2
}
res = res.toFixed(2)
// console.log(res)
res = parseFloat(res)
// console.log(Math.abs(res))
return Math.abs(res)
},
addArea (area, positions) {
let viewer = this.viewer
return viewer.entities.add({
name: '多边形面积',
position: positions[positions.length - 1],
label: {
text: area + '平方公里',
font: '20px sans-serif',
fillColor: Cesium.Color.WHITE,
outlineWidth: 2,
backgroundColor: Cesium.Color.BLACK,
showBackground: true,
style: Cesium.LabelStyle.FILL,
pixelOffset: new Cesium.Cartesian2(60, -60),
verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
horizontalOrigin: Cesium.HorizontalOrigin.CENTER,
heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
disableDepthTestDistance: Number.POSITIVE_INFINITY
}
})
},
/* 绘制函数 */
drawPointLabel (position, pointNum) {
let viewer = this.viewer
// 本质上就是添加一个点的实体
return viewer.entities.add({
name: '点几何对象',
position: position,
point: {
color: Cesium.Color.WHEAT,
pixelSize: 5,
outlineWidth: 3,
disableDepthTestDistance: Number.POSITIVE_INFINITY, //
heightReference: Cesium.HeightReference.CLAMP_TO_GROUND // 规定贴地
},
label: {
text: pointNum,
font: '30px sans-serif',
fillColor: Cesium.Color.WHITE,
outlineWidth: 2,
backgroundColor: Cesium.Color.BLACK,
showBackground: true,
style: Cesium.LabelStyle.FILL,
verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
horizontalOrigin: Cesium.HorizontalOrigin.CENTER
}
})
},
drawPoint (position) {
let viewer = this.viewer
// 本质上就是添加一个点的实体
return viewer.entities.add({
position: position,
point: {
color: Cesium.Color.WHEAT,
pixelSize: 5,
outlineWidth: 3,
disableDepthTestDistance: Number.POSITIVE_INFINITY,
heightReference: Cesium.HeightReference.CLAMP_TO_GROUND // 规定贴地
}
})
},
drawPolyline (positions) {
let viewer = this.viewer
if (positions.length < 1) return
return viewer.entities.add({
name: '线几何对象',
polyline: {
positions: positions,
width: 5.0,
material: new Cesium.PolylineGlowMaterialProperty({
// eslint-disable-next-line new-cap
color: Cesium.Color.WHEAT
}),
depthFailMaterial: new Cesium.PolylineGlowMaterialProperty({
// eslint-disable-next-line new-cap
color: Cesium.Color.WHEAT
}),
clampToGround: true
}
})
},
drawPolygon (positions) {
let viewer = this.viewer
if (positions.length < 2) return
return viewer.entities.add({
name: '面几何对象',
polygon: {
hierarchy: positions,
// eslint-disable-next-line new-cap
material: new Cesium.ColorMaterialProperty(
Cesium.Color.WHEAT.withAlpha(0.4)
)
}
})
},
/* 清除实体 */
clearAllDrawn () {
let viewer = this.viewer
this.tempEntities = []
this.pointNum = 0
viewer.entities.removeAll()
},
created () {
},
/* 根据类型绘制对象
* @param type point polyline polygon */
draw (type) {
let that = this
let viewer = this.viewer
// let pointNum = this.pointNum
// console.log(pointNum)
let tempEntities = this.tempEntities
let floatingPoint = this.floatingPoint
let activeShape = this.activeShape
let position = []
let tempPoints = []
let activeShapePoints = []
// 开启深度检测
viewer.scene.globe.depthTestAgainstTerrain = true
// 创建场景的HTML canvas元素
let handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas)
switch (type) {
// 绘制线
case 'Polyline':
// 取消鼠标双击事件
viewer.cesiumWidget.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK)
// 监听鼠标移动
handler.setInputAction(function (movement) {
if (Cesium.defined(floatingPoint)) {
let newPosition = viewer.scene.pickPosition(movement.endPosition)
if (Cesium.defined(newPosition)) {
floatingPoint.position.setValue(newPosition)
activeShapePoints.pop()
activeShapePoints.push(newPosition)
}
}
}, Cesium.ScreenSpaceEventType.MOUSE_MOVE)
// 左键单击开始画线
handler.setInputAction(function (click) {
let earthPosition = viewer.scene.pickPosition(click.position)
if (Cesium.defined(earthPosition)) {
floatingPoint = that.drawPoint(earthPosition)
}
// 获取位置信息
// 从相机位置创建一条射线,这条射线通过世界中movement.position像素所在的坐标,返回Cartesian3坐标
let ray = viewer.camera.getPickRay(click.position)
// 找到射线与渲染的地球表面之间的交点。射线必须以世界坐标给出。返回Cartesian3坐标
position = viewer.scene.globe.pick(ray, viewer.scene)
tempPoints.push(position) // 记录点位
that.pointNum += 1
let tempLength = tempPoints.length // 记录点数
// 调用绘制点的接口
let point = that.drawPointLabel(tempPoints[tempPoints.length - 1], JSON.stringify(that.pointNum))
tempEntities.push(point)
// 存在超过一个点时
if (tempLength > 1) {
// 绘制线
let pointLength = that.getLength(tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1])
let midPosition = that.getMidpoint(tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1])
let pointline = that.drawPolyline([tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1]])
let pointLabel = that.addLabel(midPosition, pointLength)
tempEntities.push(pointline) // 保存记录
tempEntities.push(pointLabel)
}
}, Cesium.ScreenSpaceEventType.LEFT_CLICK)
// 右键单击结束画线
handler.setInputAction(function (click) {
console.log(that.pointNum)
activeShapePoints.pop()
viewer.entities.remove(activeShapePoints)
viewer.entities.remove(floatingPoint)
tempPoints = [] // 清空点位记录
handler.destroy()
handler = null
floatingPoint = undefined
activeShape = undefined
activeShapePoints = []
console.log(that.pointNum)
}, Cesium.ScreenSpaceEventType.RIGHT_CLICK)
break
// 绘制面
case 'Polygon':
// 取消鼠标双击事件
viewer.cesiumWidget.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK)
// 监听鼠标移动
handler.setInputAction(function (movement) {
if (Cesium.defined(floatingPoint)) {
let newPosition = viewer.scene.pickPosition(movement.endPosition)
if (Cesium.defined(newPosition)) {
floatingPoint.position.setValue(newPosition)
activeShapePoints.pop()
activeShapePoints.push(newPosition)
}
}
}, Cesium.ScreenSpaceEventType.MOUSE_MOVE)
// 左键单击开始画线
handler.setInputAction(function (click) {
let earthPosition = viewer.scene.pickPosition(click.position)
if (Cesium.defined(earthPosition)) {
if (activeShapePoints.length === 0) {
floatingPoint = that.drawPoint(earthPosition)
activeShapePoints.push(earthPosition)
const dynamicPositions = new Cesium.CallbackProperty(function () {
return new Cesium.PolygonHierarchy(activeShapePoints)
}, false)
activeShape = that.drawPolygon(dynamicPositions)
}
activeShapePoints.push(earthPosition)
}
// 获取位置信息
let ray = viewer.camera.getPickRay(click.position)
position = viewer.scene.globe.pick(ray, viewer.scene)
tempPoints.push(position) // 记录点位
let tempLength = tempPoints.length // 记录点数
that.pointNum += 1
// 调用绘制点的接口
let point = that.drawPointLabel(tempPoints[tempPoints.length - 1], JSON.stringify(that.pointNum))
tempEntities.push(point)
// 存在超过一个点时
if (tempLength > 1) {
// 绘制线
let pointline = that.drawPolyline([tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1]])
tempEntities.push(pointline) // 保存记录
}
}, Cesium.ScreenSpaceEventType.LEFT_CLICK)
// 右键单击结束画面
handler.setInputAction(function (click) {
// 选择一个椭球或地图
let cartesian = viewer.camera.pickEllipsoid(click.position, viewer.scene.globe.ellipsoid)
if (cartesian) {
let tempLength = tempPoints.length
if (tempLength < 3) {
alert('闭合操作需要至少3个点嗷')
} else {
// 闭合最后一条线
let pointline = that.drawPolyline([tempPoints[0], tempPoints[tempPoints.length - 1]])
tempEntities.push(pointline)
that.drawPolygon(tempPoints)
let pointArea = that.getArea(tempPoints)
that.addArea(JSON.stringify(pointArea), tempPoints)
tempEntities.push(tempPoints)
handler.destroy()
handler = null
}
}
activeShapePoints.pop()
viewer.entities.remove(activeShapePoints)
viewer.entities.remove(floatingPoint)
floatingPoint = undefined
activeShapePoints = []
}, Cesium.ScreenSpaceEventType.RIGHT_CLICK)
break
}
}
}
}
</script>
<style>
html,
body {
width: 100%;
height: 100%;
padding: 0;
margin: 0;
}
#app,#cesiumContainer {
font-family: "Avenir", Helvetica, Arial, sans-serif;
width: 100%;
height: 100%;
overflow: hidden;
}
.btnContainer {
position: absolute;
left: 15px;
top: 80px;
padding: 10px 15px;
/*添加圆角边框*/
border-radius: 5px;
border: 1px solid rgba(128,128,128, 0.5);
color: #ffffff;
background: rgba(0, 0, 0,0.4);
box-shadow: 0 4px 8px rgb(128 128 128 / 50%);
max-width: 300px;
}
button {
background: transparent;
border: 1px solid #00d0ffb8;
color: white;
padding: 7px 9px;
border-radius: 3px;
cursor: pointer;
}
.tip p{
margin: 2px 0px;
padding: 5px 1px;
}
</style>
初始化部分
Init () {
// 引入个人token
Cesium.Ion.defaultAccessToken = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiJkYmJkNWQ3Mi0zOGVkLTQ5N2YtYTBmMy0wMDAyODZiMDMyZWYiLCJpZCI6ODQ2NzQsImlhdCI6MTY0NjQ0NTYxNX0.XkHX3rdysM4uUe5VTKDVEV3W2An33zyh4qAkFUac2fk'
// 设置取景器
this.viewer = new Cesium.Viewer('cesiumContainer', {
terrainProvider: Cesium.createWorldTerrain(),
selectionIndicator: false, // 不显示指示器小部件
infoBox: false, // 不显示信息框
sceneModePicker: false, // 不显示模式切换选项
baseLayerPicker: false,
navigationHelpButton: false,
animation: false,
shouldAnimate: false,
timeline: false,
geocoder: false,
homeButton: false,
// 添加ArcGIS在线影像底图
imageryProvider: new Cesium.UrlTemplateImageryProvider({
url: 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}',
subdomains: ['0', '1', '2', '3'],
tilingScheme: new Cesium.WebMercatorTilingScheme()
})
})
// 若浏览器不支持pickPosition,显示报错信息
if (!this.viewer.scene.pickPositionSupported) {
window.alert('This browser does not support pickPosition.')
}
// 载入OSM建筑物
// const osmBuildings = this.viewer.scene.primitives.add(Cesium.createOsmBuildings()) // eslint-disable-line no-unused-vars
// 初始化镜头
this.viewer.camera.lookAt(
Cesium.Cartesian3.fromDegrees(-122.2058, 46.1955, 1000.0),
new Cesium.Cartesian3(5000.0, 5000.0, 5000.0)
)
this.viewer.camera.lookAtTransform(Cesium.Matrix4.IDENTITY)
}
测距部分
/* 空间两点距离计算函数 */
getLength (start, end) {
// 将起点与终点位置信息从笛卡尔坐标形式转换为Cartographic形式
let startCartographic = Cesium.Cartographic.fromCartesian(start)
let endCartographic = Cesium.Cartographic.fromCartesian(end)
// 初始化测地线
let geodesic = new Cesium.EllipsoidGeodesic()
// 设置测地线起点和终点,EllipsoidGeodesic中setEndPoints常与surfaceDistance搭配使用
geodesic.setEndPoints(startCartographic, endCartographic)
// 获取起点和终点之间的表面距离,单位为km,规定四舍五入保留两位小数
// surfaceDistance返回number 单位为m,带小数
// console.log((geodesic.surfaceDistance / 1000).toFixed(2))
return (geodesic.surfaceDistance / 1000).toFixed(2)
},
/* 空间两点计算中点函数 */
getMidpoint (start, end) {
let startPoint = Cesium.Cartographic.fromCartesian(start)
let endPoint = Cesium.Cartographic.fromCartesian(end)
let geodesic = new Cesium.EllipsoidGeodesic()
geodesic.setEndPoints(startPoint, endPoint)
let geoPoint = geodesic.interpolateUsingFraction(0.5)
console.log(Cesium.Ellipsoid.WGS84.cartographicToCartesian(geoPoint))
return Cesium.Ellipsoid.WGS84.cartographicToCartesian(geoPoint)
},
/* 在线段中点处添加标签,显示长度 */
addLabel (midPoint, labelLength) {
let viewer = this.viewer
return viewer.entities.add({
name: '中点',
position: midPoint,
label: {
text: labelLength + 'km',
font: '20px sans-serif',
fillColor: Cesium.Color.WHITE,
outlineWidth: 2,
backgroundColor: Cesium.Color.BLACK,
showBackground: true,
style: Cesium.LabelStyle.FILL,
verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
horizontalOrigin: Cesium.HorizontalOrigin.CENTER,
heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
disableDepthTestDistance: Number.POSITIVE_INFINITY
}
})
},
测面部分
/* 测量空间面积 */
// 方向
Bearing (from, to) {
let fromCartographic = Cesium.Cartographic.fromCartesian(from)
let toCartographic = Cesium.Cartographic.fromCartesian(to)
let lat1 = fromCartographic.latitude
let lon1 = fromCartographic.longitude
let lat2 = toCartographic.latitude
let lon2 = toCartographic.longitude
let angle = -Math.atan2(Math.sin(lon1 - lon2) * Math.cos(lat2), Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2))
if (angle < 0) {
angle += Math.PI * 2.0
}
return angle
},
// 角度
pointAngle (point1, point2, point3) {
let bearing21 = this.Bearing(point2, point1)
let bearing23 = this.Bearing(point2, point3)
let angle = bearing21 - bearing23
if (angle < 0) {
angle += Math.PI * 2.0
}
return angle
},
/* 计算空间面积 */
getArea (positions) {
let res = 0
for (let i = 0; i < positions.length - 2; i++) {
let j = (i + 1) % positions.length
let k = (i + 2) % positions.length
let totalAngle = this.pointAngle(positions[i], positions[j], positions[k])
let tempLength1 = this.getLength(positions[j], positions[0])
let tempLength2 = this.getLength(positions[k], positions[0])
res += tempLength1 * tempLength2 * Math.sin(totalAngle) / 2
}
res = res.toFixed(2)
// console.log(res)
res = parseFloat(res)
// console.log(Math.abs(res))
return Math.abs(res)
},
/* 在最后一个点处添加标签,显示面积 */
addArea (area, positions) {
let viewer = this.viewer
return viewer.entities.add({
name: '多边形面积',
position: positions[positions.length - 1],
label: {
text: area + '平方公里',
font: '20px sans-serif',
fillColor: Cesium.Color.WHITE,
outlineWidth: 2,
backgroundColor: Cesium.Color.BLACK,
showBackground: true,
style: Cesium.LabelStyle.FILL,
pixelOffset: new Cesium.Cartesian2(60, -60),
verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
horizontalOrigin: Cesium.HorizontalOrigin.CENTER,
heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
disableDepthTestDistance: Number.POSITIVE_INFINITY
}
})
}
画线画面部分
/* 绘制函数 */
drawPointLabel (position, pointNum) {
let viewer = this.viewer
// 本质上就是添加一个点的实体
return viewer.entities.add({
name: '点几何对象',
position: position,
point: {
color: Cesium.Color.WHEAT,
pixelSize: 5,
outlineWidth: 3,
disableDepthTestDistance: Number.POSITIVE_INFINITY, //
heightReference: Cesium.HeightReference.CLAMP_TO_GROUND // 规定贴地
},
label: {
text: pointNum,
font: '30px sans-serif',
fillColor: Cesium.Color.WHITE,
outlineWidth: 2,
backgroundColor: Cesium.Color.BLACK,
showBackground: true,
style: Cesium.LabelStyle.FILL,
verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
horizontalOrigin: Cesium.HorizontalOrigin.CENTER
}
})
},
drawPoint (position) {
let viewer = this.viewer
// 本质上就是添加一个点的实体
return viewer.entities.add({
position: position,
point: {
color: Cesium.Color.WHEAT,
pixelSize: 5,
outlineWidth: 3,
disableDepthTestDistance: Number.POSITIVE_INFINITY,
heightReference: Cesium.HeightReference.CLAMP_TO_GROUND // 规定贴地
}
})
},
drawPolyline (positions) {
let viewer = this.viewer
if (positions.length < 1) return
return viewer.entities.add({
name: '线几何对象',
polyline: {
positions: positions,
width: 5.0,
material: new Cesium.PolylineGlowMaterialProperty({
// eslint-disable-next-line new-cap
color: Cesium.Color.WHEAT
}),
depthFailMaterial: new Cesium.PolylineGlowMaterialProperty({
// eslint-disable-next-line new-cap
color: Cesium.Color.WHEAT
}),
clampToGround: true
}
})
},
drawPolygon (positions) {
let viewer = this.viewer
if (positions.length < 2) return
return viewer.entities.add({
name: '面几何对象',
polygon: {
hierarchy: positions,
// eslint-disable-next-line new-cap
material: new Cesium.ColorMaterialProperty(
Cesium.Color.WHEAT.withAlpha(0.4)
)
}
})
},
清除绘制部分
/* 清除实体 */
clearAllDrawn () {
let viewer = this.viewer
this.tempEntities = []
this.pointNum = 0
viewer.entities.removeAll()
},
created () {
},
按钮绑定代码
/* 根据类型绘制对象
* @param type point polyline polygon */
draw (type) {
let that = this
let viewer = this.viewer
// let pointNum = this.pointNum
// console.log(pointNum)
let tempEntities = this.tempEntities
let floatingPoint = this.floatingPoint
let activeShape = this.activeShape
let position = []
let tempPoints = []
let activeShapePoints = []
// 开启深度检测
viewer.scene.globe.depthTestAgainstTerrain = true
// 创建场景的HTML canvas元素
let handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas)
switch (type) {
// 绘制线
case 'Polyline':
// 取消鼠标双击事件
viewer.cesiumWidget.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK)
// 监听鼠标移动
handler.setInputAction(function (movement) {
if (Cesium.defined(floatingPoint)) {
let newPosition = viewer.scene.pickPosition(movement.endPosition)
if (Cesium.defined(newPosition)) {
floatingPoint.position.setValue(newPosition)
activeShapePoints.pop()
activeShapePoints.push(newPosition)
}
}
}, Cesium.ScreenSpaceEventType.MOUSE_MOVE)
// 左键单击开始画线
handler.setInputAction(function (click) {
let earthPosition = viewer.scene.pickPosition(click.position)
if (Cesium.defined(earthPosition)) {
floatingPoint = that.drawPoint(earthPosition)
}
// 获取位置信息
// 从相机位置创建一条射线,这条射线通过世界中movement.position像素所在的坐标,返回Cartesian3坐标
let ray = viewer.camera.getPickRay(click.position)
// 找到射线与渲染的地球表面之间的交点。射线必须以世界坐标给出。返回Cartesian3坐标
position = viewer.scene.globe.pick(ray, viewer.scene)
tempPoints.push(position) // 记录点位
that.pointNum += 1
let tempLength = tempPoints.length // 记录点数
// 调用绘制点的接口
let point = that.drawPointLabel(tempPoints[tempPoints.length - 1], JSON.stringify(that.pointNum))
tempEntities.push(point)
// 存在超过一个点时
if (tempLength > 1) {
// 绘制线
let pointLength = that.getLength(tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1])
let midPosition = that.getMidpoint(tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1])
let pointline = that.drawPolyline([tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1]])
let pointLabel = that.addLabel(midPosition, pointLength)
tempEntities.push(pointline) // 保存记录
tempEntities.push(pointLabel)
}
}, Cesium.ScreenSpaceEventType.LEFT_CLICK)
// 右键单击结束画线
handler.setInputAction(function (click) {
console.log(that.pointNum)
activeShapePoints.pop()
viewer.entities.remove(activeShapePoints)
viewer.entities.remove(floatingPoint)
tempPoints = [] // 清空点位记录
handler.destroy()
handler = null
floatingPoint = undefined
activeShape = undefined
activeShapePoints = []
console.log(that.pointNum)
}, Cesium.ScreenSpaceEventType.RIGHT_CLICK)
break
// 绘制面
case 'Polygon':
// 取消鼠标双击事件
viewer.cesiumWidget.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK)
// 监听鼠标移动
handler.setInputAction(function (movement) {
if (Cesium.defined(floatingPoint)) {
let newPosition = viewer.scene.pickPosition(movement.endPosition)
if (Cesium.defined(newPosition)) {
floatingPoint.position.setValue(newPosition)
activeShapePoints.pop()
activeShapePoints.push(newPosition)
}
}
}, Cesium.ScreenSpaceEventType.MOUSE_MOVE)
// 左键单击开始画线
handler.setInputAction(function (click) {
let earthPosition = viewer.scene.pickPosition(click.position)
if (Cesium.defined(earthPosition)) {
if (activeShapePoints.length === 0) {
floatingPoint = that.drawPoint(earthPosition)
activeShapePoints.push(earthPosition)
const dynamicPositions = new Cesium.CallbackProperty(function () {
return new Cesium.PolygonHierarchy(activeShapePoints)
}, false)
activeShape = that.drawPolygon(dynamicPositions)
}
activeShapePoints.push(earthPosition)
}
// 获取位置信息
let ray = viewer.camera.getPickRay(click.position)
position = viewer.scene.globe.pick(ray, viewer.scene)
tempPoints.push(position) // 记录点位
let tempLength = tempPoints.length // 记录点数
that.pointNum += 1
// 调用绘制点的接口
let point = that.drawPointLabel(tempPoints[tempPoints.length - 1], JSON.stringify(that.pointNum))
tempEntities.push(point)
// 存在超过一个点时
if (tempLength > 1) {
// 绘制线
let pointline = that.drawPolyline([tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1]])
tempEntities.push(pointline) // 保存记录
}
}, Cesium.ScreenSpaceEventType.LEFT_CLICK)
// 右键单击结束画面
handler.setInputAction(function (click) {
// 选择一个椭球或地图
let cartesian = viewer.camera.pickEllipsoid(click.position, viewer.scene.globe.ellipsoid)
if (cartesian) {
let tempLength = tempPoints.length
if (tempLength < 3) {
alert('闭合操作需要至少3个点嗷')
} else {
// 闭合最后一条线
let pointline = that.drawPolyline([tempPoints[0], tempPoints[tempPoints.length - 1]])
tempEntities.push(pointline)
that.drawPolygon(tempPoints)
let pointArea = that.getArea(tempPoints)
that.addArea(JSON.stringify(pointArea), tempPoints)
tempEntities.push(tempPoints)
handler.destroy()
handler = null
}
}
activeShapePoints.pop()
viewer.entities.remove(activeShapePoints)
viewer.entities.remove(floatingPoint)
floatingPoint = undefined
activeShapePoints = []
}, Cesium.ScreenSpaceEventType.RIGHT_CLICK)
break
}
}