Cesium绘制抛物弧线，供大家参考，具体内容如下

在网上搜了很多都没有搜到，于是自己花了点时间琢磨了一下，做个记录

思路

两点连线作为坐标轴，模拟抛物线，在线上取点画直线，主要用于高度/p>

取n个点，依次画线，得到近似的抛物线，点越多越光滑

JS代码

// 两点之间抛物线绘制函数，twoPoints是一个数组：[lon1,lat1,lon2,lat2]

function animatedParabola(twoPoints) { //动态抛物线绘制

let startPoint = [twoPoints[0],twoPoints[1],0]; //起点的经度、纬度

let end = [twoPoints[2],twoPoints[3]]; //终点的经度、纬度

let step = 80; //线的数量，越多则越平滑

let heightProportion = 0.125; //最高点和总距离的比值(即图中H比上AB的值)

let dLon = (end[0] - startPoint[0])/step; //经度差值

let dLat = (end[1] - startPoint[1])/step; //纬度差值

let deltaLon = dLon * Math.abs(111000*Math.cos(twoPoints[1])); //经度差(米级)

let deltaLat = dLat * 111000; //纬度差(米),1纬度相差约111000米

let endPoint = [0,0,0]; //定义一个端点(后面将进行startPoint和endPoint两点画线)

let heigh = (step * Math.sqrt(deltaLon*deltaLon+deltaLat*deltaLat) * heightProportion).toFixed(0);

let x2 = (10000*Math.sqrt(dLon*dLon+dLat*dLat)).toFixed(0); //小数点扩大10000倍，提高精确度

let a = (heigh/(x2*x2)); //抛物线函数中的a

function y(x,height) { //模拟抛物线函数求高度

//此处模拟的函数为y = H - a*x^2 (H为高度常数)

return height - a*x*x;

}

for(let i = 1;i <= step; i++){ //逐“帧”画线

endPoint[0] = startPoint[0] + dLon; //更新end点经度

endPoint[1] = startPoint[1] + dLat; //更新end点纬度

let x = x2*(2*i/step-1); //求抛物线函数x

endPoint[2] = (y(x,heigh)).toFixed(0); //求end点高度

viewer.clock.currentTime = Cesium.JulianDate.now(); //将时钟指针移到当前时间

//这里viewer是容器初始化时new Cesium.Viewer构造的: var viewer = new Cesium.Viewer('mapContainer', {...});

let IsoTime = Cesium.JulianDate.now(); //获取当前时间

viewer.entities.add({ //添加动态线

polyline: {

positions: Cesium.Cartesian3.fromDegreesArrayHeights(startPoint.concat(endPoint)),

width: 4,

material: new Cesium.PolylineOutlineMaterialProperty({

color: Cesium.Color.GOLD,

outlineWidth: 0.3,

})

},

availability: new Cesium.TimeIntervalCollection([new Cesium.TimeInterval({ //设置显示的时间区间

start: {

dayNumber: IsoTime.dayNumber,

secondsOfDay: IsoTime.secondsOfDay+((i-1)*300),

},

stop: {

dayNumber: IsoTime.dayNumber,

secondsOfDay: IsoTime.secondsOfDay+(i*300),

},

})]),

});

viewer.entities.add({ //添加静态线

polyline: {

positions: Cesium.Cartesian3.fromDegreesArrayHeights(startPoint.concat(endPoint)),

width: 4,

material: new Cesium.PolylineGlowMaterialProperty({

color: Cesium.Color.AQUA.withAlpha(0.9),

outlineWidth: 0.3,

glowPower : 0.3,

})

},

});

// end点变为start点

startPoint[0] = endPoint[0];

startPoint[1] = endPoint[1];

startPoint[2] = endPoint[2];

}

viewer.clock.shouldAnimate = true; //启动时钟开始转动

viewer.clock.multiplier = 1600; //时钟转动速度

}

function parabola(twoPoints) { //抛物线绘制

let startPoint = [twoPoints[0],twoPoints[1],0]; //起点的经度、纬度

let end = [twoPoints[2],twoPoints[3]]; //终点的经度、纬度

let step = 80; //线的多少，越多则越平滑(但过多浏览器缓存也会占用越多)

let heightProportion = 0.125; //最高点和总距离的比值

let dLon = (end[0] - startPoint[0])/step; //经度差值

let dLat = (end[1] - startPoint[1])/step; //纬度差值

let deltaLon = dLon * Math.abs(111000*Math.cos(twoPoints[1])); //经度差(米级)

let deltaLat = dLat * 111000; //纬度差(米),1纬度相差约111000米

let endPoint = [0,0,0]; //定义一个端点(后面将进行startPoint和endPoint两点画线)

let heigh = (step * Math.sqrt(deltaLon*deltaLon+deltaLat*deltaLat) * heightProportion).toFixed(0);

let x2 = (10000*Math.sqrt(dLon*dLon+dLat*dLat)).toFixed(0); //小数点扩大10000倍，提高精确度

let a = (heigh/(x2*x2));

function y(x,height) { return height - a*x*x; }

for(var i = 1;i <= step; i++){ //逐“帧”画线

endPoint[0] = startPoint[0] + dLon; //更新end点经度

endPoint[1] = startPoint[1] + dLat; //更新end点纬度

let x = x2*(2*i/step-1); //求抛物线函数x

endPoint[2] = (y(x,heigh)).toFixed(0); //求end点高度

viewer.entities.add({ //添加静态线

polyline: {

positions: Cesium.Cartesian3.fromDegreesArrayHeights(startPoint.concat(endPoint)),

width: 4,

material: new Cesium.PolylineGlowMaterialProperty({

color: Cesium.Color.AQUA.withAlpha(0.9),

outlineWidth: 0.3,

glowPower : 0.3,

})

},

});

// end点变为start点

startPoint[0] = endPoint[0];

startPoint[1] = endPoint[1];

startPoint[2] = endPoint[2];

}

}

示例

// An Example

var viewer = new Cesium.Viewer('mapContainer');

var twoPoints = [114.3698, 22.6139, 114.2135, 22.6127];

animatedParabola(twoPoints);

运行可得到：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。