Cesium 常用标绘线、面、矩形、圆、曲面、曲线、攻击箭头、钳击箭头，标绘与修改。

前言：直接放效果图，符合就往下看，不符合出门右转。

在这里插入图片描述

由于篇幅有限，只贴出各个标绘的关键代码。

1、线段

基于坐标点，加载不同的材质。

//动态加载
const entity = this._viewer.entities.add({
   polyline: {
       positions: new CallbackProperty(() => {
           return this._positions;
       }, false),
       show: true,
       material: Color.RED,
       width: 3,
       clampToGround: true //是否贴地
   }
});

//静态
 const primitive = scene.groundPrimitives.add(
 new GroundPolylinePrimitive({
         geometryInstances: new GeometryInstance({
             geometry: new GroundPolylineGeometry({
                 positions: line,
                 width: this._width,
             }),
             id: this.id
         }),
         appearance: new PolylineMaterialAppearance({
             material:
                 Material.fromType("Image", {
                     image: this._imageUrl,
                     repeat: this._repeat
                 })
         }),
     })
 );

2、多边形

基于做坐标点，加载不同的材质

//动态
const entity = this._viewer.entities.add({
     polygon: {
         hierarchy: new CallbackProperty(() => {
             return new PolygonHierarchy(this._positions)
         }, false),
         show: true,
         fill: true,
         material: Color.RED.withAlpha(0.5),
         //@ts-ignore
         clampToGround: true,
         width: 3,
         outlineColor: Color.BLACK,
         outlineWidth: 1,
         outline: true
     }
 });
//静态
const  primite = scene.groundPrimitives.add(
  new GroundPrimitive({
        geometryInstances: new GeometryInstance({
            id: this._id,
            geometry: new PolygonGeometry({
                polygonHierarchy: {
                    positions: positions,
                    holes: []
                },
            }),
        }),
        appearance: new EllipsoidSurfaceAppearance({
            material: Material.fromType("Grid", this._grid)
        }),
        classificationType: ClassificationType.TERRAIN,
    })
)

3、绘制直线箭头

根据箭头算法，提供两个点的坐标

//动态
const arrowEntity = this._viewer.entities.add({
   polygon: {
       hierarchy: new CallbackProperty(() => {
           const length = this._positions.length;
           const p1 = this._positions[0];
           const p2 = this._positions[length - 1];
           const firstPoint = this.cartesianToLatlng(p1);
           const endPoints = this.cartesianToLatlng(p2);
           let arrow = [];
           let res = this.fineArrow([firstPoint[0], firstPoint[1]], [endPoints[0], endPoints[1]]);
           if (res) {
               for (let i = 0; i < res.length; i++) {
                   let cart3 = new Cartesian3(res[i].x, res[i].y, res[i].z);
                   arrow.push(cart3);
               }
               return new PolygonHierarchy(arrow);
           }
       }, false),
       show: true,
       fill: true,
       material: Color.RED.withAlpha(0.5)
   }
})

箭头算法

/**
 * 
 * @param t 二维坐标
 * @param o 二维坐标
 * @returns 两点之间的距离
 */
export function distance(t: number[], o: number[]) {
  return Math.sqrt(Math.pow(t[0] - o[0], 2) + Math.pow(t[1] - o[1], 2));
}
/**
 * 
 * @param positionArr 点坐标数组
 * @returns 距离
 */
export function wholeDistance(positionArr: number[][]) {
  let dis = 0;
  const length = positionArr.length - 1;
  for (let i = 0; i < length; i++) {
    dis += distance(positionArr[i], positionArr[i + 1]);
  }
  return dis;
}
export function getBaseLength(positionArr: number[][]) {
  return Math.pow(wholeDistance(positionArr), 0.99);
}

/**
 * 
 * @param t 
 * @param o 
 * @param e 
 * @param r 
 * @param n 
 * @returns 获取第三个点的坐标 
 */
export function getThirdPoint(
  t: number[],
  o: number[],
  e: number,
  r: number,
  n: boolean = false
) {
  let g = getAzimuth(t, o),
    i = n ? g + e : g - e,
    s = r * Math.cos(i),
    a = r * Math.sin(i);
  return [o[0] + s, o[1] + a];
}
/**
 * 
 * @param t 
 * @param o 
 * @returns 获取方位角
 */
export function getAzimuth(t: number[], o: number[]): number {
  let e = 0,
    r = Math.asin(Math.abs(o[1] - t[1]) / distance(t, o));
  o[1] >= t[1] && o[0] >= t[0]
    ? (e = r + Math.PI)
    : o[1] >= t[1] && o[0] < t[0]
      ? (e = 2 * Math.PI - r)
      : o[1] < t[1] && o[0] < t[0]
        ? (e = r)
        : o[1] < t[1] && o[0] >= t[0]
          ? (e = Math.PI - r)
          : 0;
  return e;
}
fineArrowDefualParam() {
   return {
       tailWidthFactor: 0.15,
       neckWidthFactor: 0.2,
       headWidthFactor: 0.25,
       headAngle: Math['PI'] / 8.5,
       neckAngle: Math['PI'] / 0xd
   };
}
fineArrow(po1: number[], po2: number[]) {
    if ((po1.length < 2) || (po2.length < 2)) return;
    //画箭头的函数
    let tailWidthFactor = this.fineArrowDefualParam().tailWidthFactor;
    let neckWidthFactor = this.fineArrowDefualParam().neckWidthFactor;
    let headWidthFactor = this.fineArrowDefualParam().headWidthFactor;
    let headAngle = this.fineArrowDefualParam().headAngle;
    let neckAngle = this.fineArrowDefualParam().neckAngle;
    let o = [];
    o[0] = po1;
    o[1] = po2;
    var e = o[0],
        r = o[1],
        n = getBaseLength(o),
        g = n * tailWidthFactor,
        //尾部宽度因子
        i = n * neckWidthFactor,
        //脖子宽度银子
        s = n * headWidthFactor,
        //头部宽度因子
        a = getThirdPoint(r, e, Math.PI / 2, g, !0),
        l = getThirdPoint(r, e, Math.PI / 2, g, !1),
        u = getThirdPoint(e, r, headAngle, s, !1),
        c = getThirdPoint(e, r, headAngle, s, !0),
        p = getThirdPoint(e, r, neckAngle, i, !1),
        h = getThirdPoint(e, r, neckAngle, i, !0),
        d = [];
    d.push(a[0], a[1], p[0], p[1], u[0], u[1], r[0], r[1], c[0], c[1], h[0], h[1], l[0], l[1], e[0], e[1]);
    return Cartesian3.fromDegreesArray(d)
}

4、攻击箭头

提供坐标点绘制攻击箭头也叫燕尾箭头

import initXp from 'algorithm.js'
//动态
const xp = initXp()
const update = () => {
     //计算面
     if (positions.length < 3) {
         return null;
     }
     let lnglatArr = [], lnglat;
     for (var i = 0; i < positions.length; i++) {
         lnglat = this.cartesianToLatlng(positions[i]);
         lnglatArr.push(lnglat)
     }
     const res = xp.algorithm.tailedAttackArrow(lnglatArr);
     const returnData = res.polygonalPoint;
     return new PolygonHierarchy(returnData);
 }
this._viewer.entities.add({
  polygon: new PolygonGraphics({
       hierarchy: new CallbackProperty(update, false),
       show: true,
       fill: true,
       material: this.fillMaterial
   })
});

function cartesianToLatlng(position: Cartesian3) {
   const latlng =
       this._viewer.scene.globe.ellipsoid.cartesianToCartographic(position);
   const lat = CesiumMath.toDegrees(latlng.latitude);
   const lng = CesiumMath.toDegrees(latlng.longitude);
   return [lng, lat];
}

5、钳击箭头

一共需要提供五个点

 const update = () => {
  //计算面
    if (positions.length < 3) {
        return null;
    }
    var lnglatArr = [];
    for (var i = 0; i < positions.length; i++) {
        var lnglat = this.cartesianToLatlng(positions[i]);
        lnglatArr.push(lnglat)
    }
    const xp = initXp()
    let res = xp.algorithm.doubleArrow(lnglatArr);
    const returnData = res.polygonalPoint;
    return new PolygonHierarchy(returnData);
}
return this._viewer.entities.add({
    polygon: new PolygonGraphics({
        hierarchy: new CallbackProperty(update, false),
        show: true,
        fill: true,
        material: this.fillMaterial
    })
});

function cartesianToLatlng(position: Cartesian3) {
  const latlng =
      this._viewer.scene.globe.ellipsoid.cartesianToCartographic(position);
  const lat = CesiumMath.toDegrees(latlng.latitude);
  const lng = CesiumMath.toDegrees(latlng.longitude);
  return [lng, lat];
}

6、矩形

提供两个点

import { point } from "@turf/helpers"
import rhumbBearing from "@turf/rhumb-bearing"
import distance from "@turf/distance"
import destination from "@turf/destination"
const entity = this._viewer.entities.add({
 polygon: {
      hierarchy: new CallbackProperty(() => {

          if (this._positions[0] && this._positions[1] && this._positions[2]) {
              const r0 = Cartographic.fromCartesian(this._positions[0])
              const r1 = Cartographic.fromCartesian(this._positions[1]) // 辅助点
              const r2 = Cartographic.fromCartesian(this._positions[2])

              const p0 = point([r0.longitude * 180 / Math.PI, r0.latitude * 180 / Math.PI])
              const p1 = point([r1.longitude * 180 / Math.PI, r1.latitude * 180 / Math.PI])
              const p2 = point([r2.longitude * 180 / Math.PI, r2.latitude * 180 / Math.PI])

              const bearing1 = rhumbBearing(p0, p1)
              const bearing2 = rhumbBearing(p0, p2)
              const angle1 = bearing2 - bearing1

              // 对角长度
              const length = distance(p0, p2, { units: 'miles' })

              const len1 = Math.cos(angle1 / 180 * Math.PI) * length
              const dest1 = destination(p0, len1, bearing1, { units: 'miles' })

              const angle2 = 90 - angle1
              const len2 = Math.cos(angle2 / 180 * Math.PI) * length
              const dest2 = destination(p0, len2, 90 + bearing1, { units: 'miles' })
              //@ts-ignore
              const coordinates = [this._positions[0], Cartesian3.fromDegrees(...dest1.geometry.coordinates), this._positions[2], Cartesian3.fromDegrees(...dest2.geometry.coordinates)]

              return new PolygonHierarchy(coordinates)
          }

      }, false),
      material: this._color
  },
})

7、绘制椭圆

绘制椭圆需要两个点，注意长轴必须大于短轴，长短轴一致时为圆

import { point } from "@turf/helpers"
import distance from "@turf/distance"
const entity = this._viewer.entities.add({
  //@ts-ignore
    position: new CallbackProperty(() => {
        return this._positions[0]
    }, false),
    ellipse: {
        // 半短轴（画圆：半短轴和半长轴一致即可）
        semiMinorAxis: new CallbackProperty(() => {
            const r0 = Cartographic.fromCartesian(this._positions[0])
            const r1 = Cartographic.fromCartesian(this._positions[1])
            const p0 = point([r0.longitude * 180 / Math.PI, r0.latitude * 180 / Math.PI])
            let p3 = point([r1.longitude * 180 / Math.PI, r1.latitude * 180 / Math.PI])
            if (this._isEllipse) {
                let p1 = point([r1.longitude * 180 / Math.PI, r0.latitude * 180 / Math.PI])
                let p2 = point([r0.longitude * 180 / Math.PI, r1.latitude * 180 / Math.PI])
                let len1, len2
                len1 = distance(p0, p1, { units: 'kilometers' }) * 1000
                len2 = distance(p0, p2, { units: 'kilometers' }) * 1000
                return len1 < len2 ? len1 : len2
            } else return distance(p0, p3, { units: 'kilometers' }) * 1000
        }, false),
        // 半长轴
        semiMajorAxis: new CallbackProperty(() => {
            const r0 = Cartographic.fromCartesian(this._positions[0])
            const r1 = Cartographic.fromCartesian(this._positions[1])
            const p0 = point([r0.longitude * 180 / Math.PI, r0.latitude * 180 / Math.PI])
            let p3 = point([r1.longitude * 180 / Math.PI, r1.latitude * 180 / Math.PI])
            if (this._isEllipse) {
                let p1 = point([r1.longitude * 180 / Math.PI, r0.latitude * 180 / Math.PI])
                let p2 = point([r0.longitude * 180 / Math.PI, r1.latitude * 180 / Math.PI])
                let len1, len2
                len1 = distance(p0, p1, { units: 'kilometers' }) * 1000
                len2 = distance(p0, p2, { units: 'kilometers' }) * 1000
                return len1 > len2 ? len1 : len2
            } else return distance(p0, p3, { units: 'kilometers' }) * 1000
        }, false),
        // 填充色
        material: this._color,
    },
});

8、绘制曲线

绘制曲线利用bezier算法

import { lineString, bezierSpline } from '@turf/turf'

const entity = this._viewer.entities.add({
   polyline: {
       positions: new CallbackProperty(() => {
           const lngLatPoints = this._positions.map(i => this.cartesianToLatlng(i))
           const pos = bezierSpline(lineString(lngLatPoints)).geometry.coordinates
           return Cartesian3.fromDegreesArray(pos.flat())
       }, false),
       show: true,
       material: Color.RED,
       width: 3,
       clampToGround: true //是否贴地
   }
});

9、绘制封闭曲面

根据turf

 const entity = this._viewer.entities.add({
   polygon: {
         hierarchy: new CallbackProperty(() => {
             if (this._positions.length < 2) return []
             let pnts = []
             for (let p = 0; p < this._positions.length; p++) {
                 pnts.push(this.cartesianToLatlng(this._positions[p]))
             }
             pnts.push(pnts[0], pnts[1])
             let normals: number[][] = []
             let pList: Cartesian3[] = []
             for (let i = 0; i < pnts.length - 2; i++) {
                 let normalPoints = this.getBisectorNormals(this._t, pnts[i], pnts[i + 1], pnts[i + 2])
                 normals = normals.concat(normalPoints)
             }
             let count = normals.length
             normals = [normals[count - 1]].concat(normals.slice(0, count - 1))
             for (let i = 0; i < pnts.length - 2; i++) {
                 let pnt1 = pnts[i]
                 let pnt2 = pnts[i + 1]
                 pList.push(this.latlngTocartesian(pnt1))
                 for (let t = 0; t <= this._FITTING_COUNT; t++) {
                     let pnt = this.getCubicValue(t / this._FITTING_COUNT, pnt1, normals[i * 2], normals[i * 2 + 1], pnt2)
                     pList.push(this.latlngTocartesian(pnt))
                 }
                 pList.push(this.latlngTocartesian(pnt2))
             }
             return new PolygonHierarchy(pList)
         }, false),
         show: true,
         fill: true,
         material: Color.RED.withAlpha(0.5),
         //@ts-ignore
         clampToGround: true,
         width: 3,
         outlineColor: Color.BLACK,
         outlineWidth: 1,
         outline: true
     }
 });
 function getBisectorNormals(t: number, pnt1: number[], pnt2: number[], pnt3: number[]): number[][] {
        let normal = this.getNormal(pnt1, pnt2, pnt3)
        let bisectorNormalRight: number[] = []
        let bisectorNormalLeft: number[] = []
        let dt: number, x: number, y: number
        let dist = Math.sqrt(normal[0] * normal[0] + normal[1] * normal[1])
        let uX = normal[0] / dist
        let uY = normal[1] / dist
        let d1 = this.mathDistance(pnt1, pnt2)
        let d2 = this.mathDistance(pnt2, pnt3)

        if (dist > this._ZERO_TOLERANCE) {
            if (this.isClockWise(pnt1, pnt2, pnt3)) {
                dt = t * d1
                x = pnt2[0] - dt * uY
                y = pnt2[1] + dt * uX
                bisectorNormalRight = [x, y]
                dt = t * d2
                x = pnt2[0] + dt * uY
                y = pnt2[1] - dt * uX
                bisectorNormalLeft = [x, y]
            } else {
                dt = t * d1
                x = pnt2[0] + dt * uY
                y = pnt2[1] - dt * uX
                bisectorNormalRight = [x, y]
                dt = t * d2
                x = pnt2[0] - dt * uY
                y = pnt2[1] + dt * uX
                bisectorNormalLeft = [x, y]
            }
        } else {
            x = pnt2[0] + t * (pnt1[0] - pnt2[0])
            y = pnt2[1] + t * (pnt1[1] - pnt2[1])
            bisectorNormalRight = [x, y]
            x = pnt2[0] + t * (pnt3[0] - pnt2[0])
            y = pnt2[1] + t * (pnt3[1] - pnt2[1])
            bisectorNormalLeft = [x, y]
        }
        return [bisectorNormalRight, bisectorNormalLeft]
    }
     getNormal(pnt1: number[], pnt2: number[], pnt3: number[]) {
        let dX1 = pnt1[0] - pnt2[0]
        let dY1 = pnt1[1] - pnt2[1]
        let d1 = Math.sqrt(dX1 * dX1 + dY1 * dY1)
        dX1 /= d1
        dY1 /= d1
        let dX2 = pnt3[0] - pnt2[0]
        let dY2 = pnt3[1] - pnt2[1]
        let d2 = Math.sqrt(dX2 * dX2 + dY2 * dY2)
        dX2 /= d2
        dY2 /= d2
        let uX = dX1 + dX2
        let uY = dY1 + dY2
        return [uX, uY]
    }
    function mathDistance(pnt1: number[], pnt2: number[]) {
        return (Math.sqrt(Math.pow((pnt1[0] - pnt2[0]), 2) + Math.pow((pnt1[1] - pnt2[1]), 2)))
    }
    function isClockWise(pnt1: number[], pnt2: number[], pnt3: number[]) {
        return ((pnt3[1] - pnt1[1]) * (pnt2[0] - pnt1[0]) > (pnt2[1] - pnt1[1]) * (pnt3[0] - pnt1[0]))
    }