使用Cesium动态绘制点、线、面、圆、矩形
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2022-05-27 14:37:42
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将以下代码复制到https://cesiumjs.org/Cesium/Build/Apps/Sandcastle/?src=Drawing%20on%20Terrain.html查看Demo。
var activeShapePoints = [];
var activeShape;
var floatingPoint;
//查看器
var viewer = new Cesium.Viewer('cesiumContainer', {
selectionIndicator: false,
infoBox: false,
terrainProvider: Cesium.createWorldTerrain()
});
var handler = new Cesium.ScreenSpaceEventHandler(viewer.canvas);
//双击鼠标左键清除默认事件
viewer.cesiumWidget.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
//绘制点
function createPoint(worldPosition) {
var point = viewer.entities.add({
position: worldPosition,
point: {
color: Cesium.Color.WHITE,
pixelSize: 5,
heightReference: Cesium.HeightReference.CLAMP_TO_GROUND
}
});
return point;
}
//初始化为线
var drawingMode = 'line';
//绘制图形
function drawShape(positionData) {
var shape;
if (drawingMode === 'line') {
shape = viewer.entities.add({
polyline: {
positions: positionData,
clampToGround: true,
width: 3
}
});
}
else if (drawingMode === 'polygon') {
shape = viewer.entities.add({
polygon: {
hierarchy: positionData,
material: new Cesium.ColorMaterialProperty(Cesium.Color.WHITE.withAlpha(0.7))
}
});
} else if (drawingMode === 'circle') {
//当positionData为数组时绘制最终图,如果为function则绘制动态图
var value = typeof positionData.getValue === 'function' ? positionData.getValue(0) : positionData;
//var start = activeShapePoints[0];
//var end = activeShapePoints[activeShapePoints.length - 1];
//var r = Math.sqrt(Math.pow(start.x - end.x, 2) + Math.pow(start.y - end.y, 2));
//r = r ? r : r + 1;
shape = viewer.entities.add({
position: activeShapePoints[0],
name: 'Blue translucent, rotated, and extruded ellipse with outline',
type:'Selection tool',
ellipse: {
semiMinorAxis: new Cesium.CallbackProperty(function () {
//半径 两点间距离
var r = Math.sqrt(Math.pow(value[0].x - value[value.length - 1].x, 2) + Math.pow(value[0].y - value[value.length - 1].y, 2));
return r ? r : r + 1;
}, false),
semiMajorAxis: new Cesium.CallbackProperty(function () {
var r = Math.sqrt(Math.pow(value[0].x - value[value.length - 1].x, 2) + Math.pow(value[0].y - value[value.length - 1].y, 2));
return r ? r : r + 1;
}, false),
material: Cesium.Color.BLUE.withAlpha(0.5),
outline: true
}
});
} else if (drawingMode === 'rectangle') {
//当positionData为数组时绘制最终图,如果为function则绘制动态图
var arr = typeof positionData.getValue === 'function' ? positionData.getValue(0) : positionData;
shape = viewer.entities.add({
name: 'Blue translucent, rotated, and extruded ellipse with outline',
rectangle : {
coordinates : new Cesium.CallbackProperty(function () {
var obj=Cesium.Rectangle.fromCartesianArray(arr);
//if(obj.west==obj.east){ obj.east+=0.000001};
//if(obj.south==obj.north){obj.north+=0.000001};
return obj;
}, false),
material : Cesium.Color.RED.withAlpha(0.5)
}
});
}
return shape;
}
//鼠标左键
handler.setInputAction(function (event) {
// We use `viewer.scene.pickPosition` here instead of `viewer.camera.pickEllipsoid` so that
// we get the correct point when mousing over terrain.
var earthPosition = viewer.scene.pickPosition(event.position);
// `earthPosition` will be undefined if our mouse is not over the globe.
if (Cesium.defined(earthPosition)) {
if (activeShapePoints.length === 0) {
floatingPoint = createPoint(earthPosition);
activeShapePoints.push(earthPosition);
var dynamicPositions = new Cesium.CallbackProperty(function () {
return activeShapePoints;
}, false);
activeShape = drawShape(dynamicPositions);//绘制动态图
}
activeShapePoints.push(earthPosition);
createPoint(earthPosition);
}
}, Cesium.ScreenSpaceEventType.LEFT_CLICK);
//鼠标移动
handler.setInputAction(function (event) {
if (Cesium.defined(floatingPoint)) {
var newPosition = viewer.scene.pickPosition(event.endPosition);
if (Cesium.defined(newPosition)) {
floatingPoint.position.setValue(newPosition);
activeShapePoints.pop();
activeShapePoints.push(newPosition);
}
}
}, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
// Redraw the shape so it's not dynamic and remove the dynamic shape.
function terminateShape() {
activeShapePoints.pop();//去除最后一个动态点
if(activeShapePoints.length){
drawShape(activeShapePoints);//绘制最终图
}
viewer.entities.remove(floatingPoint);//去除动态点图形(当前鼠标点)
viewer.entities.remove(activeShape);//去除动态图形
floatingPoint = undefined;
activeShape = undefined;
activeShapePoints = [];
}
handler.setInputAction(function (event) {
terminateShape();
}, Cesium.ScreenSpaceEventType.RIGHT_CLICK);
var options = [{
text: 'Draw Lines',
onselect: function () {
terminateShape();
drawingMode = 'line';
}
}, {
text: 'Draw Polygons',
onselect: function () {
terminateShape();
drawingMode = 'polygon';
}
}, {
text: 'Draw Circle',
onselect: function () {
terminateShape();
drawingMode = 'circle';
}
}, {
text: 'Draw Rectangle',
onselect: function () {
terminateShape();
drawingMode = 'rectangle';
}
}];
Sandcastle.addToolbarMenu(options);
// Zoom in to an area with mountains
viewer.camera.lookAt(Cesium.Cartesian3.fromDegrees(-122.2058, 46.1955, 1000.0), new Cesium.Cartesian3(5000.0, 5000.0, 5000.0));
viewer.camera.lookAtTransform(Cesium.Matrix4.IDENTITY);
参考 https://github.com/K-UTIL/cesiumjs-demo/blob/master/Source/demo.js
https://blog.csdn.net/weixin_33774883/article/details/87495638