【Cesium开发实战】飞行漫游功能的实现，可设置漫游路径，漫游高度，暂停，继续，删除路径

Cesium有很多很强大的功能，可以在地球上实现很多炫酷的3D效果。今天给大家分享一个可自定义的漫游飞行功能。

1.话不多说，先展示

2.设计思路

项目需求，可自定义漫游路径，并且设置高度，暂停，继续，删除等功能。点击绘制开始在地图上绘制漫游的路径点位，双击结束后可编辑漫游路径名和漫游的高度设置。点击飞行，创建模型，使模型按照设定的点位和高度进行漫游。

3.具体代码

<template>
	<div class="page">
		<el-button @click="drawLineRoad">绘制</el-button>
		<el-table :data="dataList" border>
			<el-table-column prop="name" label="名称" align="center" />
			<el-table-column prop="action" label="操作" align="center">
				<template #default="scope">
					<el-button type="primary" style="width: 30px" @click="startFly(scope.row, scope.$index)">飞行</el-button>
					<el-button type="primary" style="width: 30px" @click="stopFly()">暂停</el-button>
					<el-button type="primary" style="width: 30px" @click="continueFly()">继续</el-button>
					<el-button link type="primary" size="small" @click="delEntity(scope.row, scope.$index)"
						><el-icon :size="16"><ele-Delete /> </el-icon
					></el-button>
				</template>
			</el-table-column>
		</el-table>
	</div>
	<el-dialog v-model="dialogFormVisible" title="配置" width="500" :close-on-press-escape="false" :close-on-click-modal="false" :show-close="false">
		<el-form ref="formRef" :model="form" label-width="auto" :rules="rules">
			<el-form-item label="漫游路径名称" prop="title">
				<el-input v-model="form.title" placeholder="请输入" />
			</el-form-item>
			<el-form-item label="漫游高度">
				<el-input-number :min="0" v-model="form.height" placeholder="请输入" />
			</el-form-item>
		</el-form>

		<template #footer>
			<div class="dialog-footer">
				<el-button type="primary" @click="submitForm(formRef)"> 确定 </el-button>
			</div>
		</template>
	</el-dialog>
</template>

<script setup lang="ts">
import { onMounted, onUnmounted, reactive, ref } from 'vue';
import { Cesium } from '/@/utils/cesium';

const props = defineProps(['viewer']);

const dialogFormVisible = ref(false);

var handler: any = null;

const formRef = ref();

const rules = {
	title: { required: true, message: '请输入漫游路径名称', trigger: 'blur' },
};

//漫游名称
const form = reactive({
	title: '',
	height: 300,
});

//是否开始绘制
const drawing = ref(false);

//列表数据
const dataList: any = reactive([]);

//绘制的所有地面的点线实体集合
var entities: any = [];
//临时一条数据的point实体列表
var pointEntities: any = [];
//临时一条数据的线实体列表
var linesEntities: any = [];

var activeShapePoints: any = [];
//构建列表一条数据的数据，经纬度高度。
var customMarks: any = [];

var floatingPoint: any = undefined;
var activeShape: any = undefined;

//绘制线路
const drawLineRoad = () => {
	drawing.value = true;
	handler = new Cesium.ScreenSpaceEventHandler(props.viewer.scene.canvas);
	//鼠标左键
	handler.setInputAction(function (event: any) {
		if (drawing.value) {
			var earthPosition = props.viewer.scene.pickPosition(event.position);
			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
					//线实体集合
					linesEntities.push(activeShape);
				}
				activeShapePoints.push(earthPosition);
				//点实体集合
				pointEntities.push(createPoint(earthPosition));
			}
		}
	}, Cesium.ScreenSpaceEventType.LEFT_CLICK);
	//鼠标移动
	handler.setInputAction(function (event: any) {
		if (Cesium.defined(floatingPoint)) {
			var newPosition = props.viewer.scene.pickPosition(event.endPosition);
			if (Cesium.defined(newPosition)) {
				floatingPoint.position.setValue(newPosition);
				activeShapePoints.pop();
				activeShapePoints.push(newPosition);
			}
		}
	}, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
	handler.setInputAction(function () {
		if (drawing.value) {
			drawing.value = false;
			terminateShape();
		}
	}, Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
};

//绘制点
const createPoint = (worldPosition: any) => {
	var point = props.viewer.entities.add({
		position: worldPosition,
		point: {
			color: Cesium.Color.RED,
			pixelSize: 10,
			heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
		},
	});
	return point;
};

//绘制线
const drawShape = (positionData: any) => {
	var shape = props.viewer.entities.add({
		polyline: {
			with: 10,
			color: Cesium.Color.RED,
			positions: positionData,
			clampToGround: true,
		},
	});
	return shape;
};

//双击后处理数据
const terminateShape = () => {
	linesEntities.push(drawShape(activeShapePoints)); //绘制最终图

	//因双击会触发俩次单机事件，去除最后一个点重复绘制，并删除多余的点
	props.viewer.entities.remove(pointEntities[pointEntities.length - 1]);
	pointEntities.pop();

	dialogFormVisible.value = true; //弹出对话框

	props.viewer.entities.remove(floatingPoint); //去除动态点图形（当前鼠标点）
	props.viewer.entities.remove(activeShape); //去除动态图形
	floatingPoint = undefined;
	activeShape = undefined;
	activeShapePoints = [];
	props.viewer.trackedEntity = null;
};

/**
 * 点击确定
 */
const submitForm = async (formEl: any) => {
	const valid = await formEl.validate();
	if (valid) {
		//创建条目列表数据
		if (pointEntities.length) {
			for (const item of pointEntities) {
				const latitude = toDegrees(Cesium.Cartographic.fromCartesian(item.position._value).latitude);
				const longitude = toDegrees(Cesium.Cartographic.fromCartesian(item.position._value).longitude);
				customMarks.push({ longitude: longitude, latitude: latitude, height: form.height });
			}
		}

		addElectronicFence(form.title, customMarks);
		customMarks = [];
		//重置默认高度
		form.height = 300;
		dialogFormVisible.value = false;
		formEl.resetFields();
	}
};

/**
 * 添加列表数据
 */
var addElectronicFence = (name: string, positions: any) => {
	//点实体和线实体的集合
	entities.push({
		pointEntities: pointEntities,
		linesEntities: linesEntities,
	});

	dataList.push({
		id: Cesium.createGuid(),
		name: name,
		positions: positions,
	});

	pointEntities = [];
	linesEntities = [];

	//移除点击事件
	handler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_CLICK);
	handler.removeInputAction(Cesium.ScreenSpaceEventType.MOUSE_MOVE);
	handler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
};

/**
 * 删除已绘制的图形
 */
const delEntity = (item: any, index: number) => {
	//如果删除的是当前飞行的路线 暂停飞行并删除飞机实体
	if (item.id == airplaneEntity.id) {
		stopFly();
		props.viewer.entities.remove(airplaneEntity);
	}

	//循环删除条目上的实体点  和  实体线
	for (const obj of entities[index].pointEntities) {
		props.viewer.entities.remove(obj);
	}
	for (const obj of entities[index].linesEntities) {
		props.viewer.entities.remove(obj);
	}
	//删除当前条目的数据
	entities.splice(index, 1);
	dataList.splice(index, 1);
};

const positionProperty = new Cesium.SampledPositionProperty();
// 时间的间隔
const timeStepInSeconds = 10;
var airplaneEntity: any;

//开始飞行
const startFly = (item: any, index: number) => {
	//当下个飞行前清除上次的飞行对象和路径
	if (airplaneEntity != null) {
		props.viewer.entities.remove(airplaneEntity);
	}
	//获取条目经纬度数据集合
	let flightData = item.positions;
	const totalSeconds = (flightData.length - 1) * timeStepInSeconds;
	// 设置起点时间
	const time = new Date('2020-03-09T23:10:00Z');
	const start = Cesium.JulianDate.fromDate(time);
	// 设置终点时间
	const stop = Cesium.JulianDate.addSeconds(start, totalSeconds, new Cesium.JulianDate());

	props.viewer.clock.startTime = start.clone();
	props.viewer.clock.stopTime = stop.clone();
	props.viewer.clock.currentTime = start.clone();
	// 设置进度条，从哪里开始到哪里结束
	props.viewer.timeline.zoomTo(start, stop);
	for (let i = 0; i < flightData.length; i++) {
		const dataPoint = flightData[i];
		// 采样时间
		const time = Cesium.JulianDate.addSeconds(start, i * timeStepInSeconds, new Cesium.JulianDate());

		// 计算当前的3D坐标
		const position = Cesium.Cartesian3.fromDegrees(dataPoint.longitude, dataPoint.latitude, dataPoint.height);

		// 添加轨迹采样点
		positionProperty.addSample(time, position);

		// 添加物体点
		// props.viewer.entities.add({
		// 	position: position,
		// 	point: {
		// 		pixelSize: 10,
		// 		color: new Cesium.Color(0.7, 0.8, 0, 0.7),
		// 	},
		// });
	}

	// 创建飞机
	airplaneEntity = props.viewer.entities.add({
		id: item.id,
		availability: new Cesium.TimeIntervalCollection([
			new Cesium.TimeInterval({
				start: start,
				stop: stop,
			}),
		]),
		position: positionProperty,
		model: {
			uri: '/src/assets/cesium/Cesium_Air.glb',
		},
		// 自动计算前进方向
		orientation: new Cesium.VelocityOrientationProperty(positionProperty),
		// 绘制轨迹线
		path: new Cesium.PathGraphics({
			width: 3,
		}),
	});

	// 设置相机追踪运动物体
	props.viewer.trackedEntity = airplaneEntity;

	// 设置时间速率
	props.viewer.clock.multiplier = 1;

	// 设置自动播放
	props.viewer.clock.shouldAnimate = true;
	// setTimeout(() => {
	// 	props.viewer.clock.shouldAnimate = true;
	// }, 5000);
};
//停止飞行
const stopFly = () => {
	props.viewer.clock.shouldAnimate = false;
};
//继续飞行
const continueFly = () => {
	props.viewer.clock.shouldAnimate = true;
};

// 弧度转角度
const toDegrees = (radians: any) => {
	return (radians * 180) / Math.PI;
};
// 角度转弧度
const toRadians = (degrees: any) => {
	return (degrees * Math.PI) / 180;
};

onMounted(() => {});

onUnmounted(() => {
	//清除绘制的内容
	props.viewer.entities.removeAll();
	if (handler != null) {
		handler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_CLICK);
		handler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
	}
});
</script>

<style scoped>
.page {
	position: absolute;
	right: 10px;
	top: 10px;
	color: #fff;
	background: #fff;
	padding: 10px;
	border-radius: 5px;
	width: 400px;
}
</style>