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高度的电子围栏。

1.话不多说，先展示。

2.设计思路

点击绘制，在地图上可绘制多个点位，双击结束绘制，可对电子围栏起名称以及自定义电子围栏高度，并以列表形式展示，可同时绘制多个电子围栏，点击列表可飞行至对应的电子围栏，也可删除对应的电子围栏。

3.具体代码

<template>
	<div class="page">
		<el-button @click="draw">绘制</el-button>
		<el-table :data="dataList" border @row-click="rowClick">
			<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 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="电子围栏名称" prop="title">
				<el-input v-model="form.title" placeholder="请输入" />
			</el-form-item>
			<el-form-item label="电子围栏高度">
				<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 { Cesium } from '/@/utils/cesium';
import { onMounted, onUnmounted, reactive, ref } from 'vue';
import { debounce } from 'lodash';

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

const dialogFormVisible = ref(false);

var handler: any = null;

const formRef = ref();

const rules = {
	title: { required: true, message: '请输入电子围栏名称', trigger: 'blur' },
};

// 视点名称
const form = reactive({
	title: '',
	height: 100,
});

var flyOption = {
	offset: {
		heading: Cesium.Math.toRadians(1.0114629015290062),
		pitch: Cesium.Math.toRadians(-23.53661660731824),
		roll: Cesium.Math.toRadians(0.00324596311071617),
	},
};
/**
 * 添加电子围栏
 */
var addElectronicFence = (name: string, positions: any) => {
	let material = getCustomMaterialWall({
		image: '/src/assets/cesium/wall.png',
		freely: 'vertical',
		direction: '+',
		count: 2,
		color: Cesium.Color.RED,
		duration: 2000,
	});

	var geometry = props.viewer.entities.add({
		id: new Date().getTime(),
		name: name,
		wall: {
			positions: Cesium.Cartesian3.fromDegreesArrayHeights(positions),
			material: material,
		},
	});

	entities.push(geometry);
	dataList.push({
		id: geometry.id,
		name: geometry.name,
		positions: positions,
	});
};

var getCustomMaterialWall = (options: any) => {
	if (props.viewer && options && options.image) {
		return _initWallCustomMaterialProperty(options);
	}
};

// 动态初始化材质线
var _initWallCustomMaterialProperty = (options: any) => {
	var Color = Cesium.Color,
		defaultValue = Cesium.defaultValue,
		defined = Cesium.defined,
		defineProperties = Object.defineProperties,
		Event = Cesium.Event,
		createPropertyDescriptor = Cesium.createPropertyDescriptor,
		Property = Cesium.Property,
		Material = Cesium.Material,
		MaterialType = options.MaterialType || 'wallType' + parseInt(Math.random() * 1000);

	function WallLinkCustomMaterialProperty(options) {
		options = defaultValue(options, defaultValue.EMPTY_OBJECT);
		this._definitionChanged = new Event();
		this._color = undefined;
		this._colorSubscription = undefined;
		this.color = options.color || Color.BLUE;
		this.duration = options.duration || 3000;
		this._time = new Date().getTime();
	}

	defineProperties(WallLinkCustomMaterialProperty.prototype, {
		isvarant: {
			get: function () {
				return false;
			},
		},
		definitionChanged: {
			get: function () {
				return this._definitionChanged;
			},
		},
		color: createPropertyDescriptor('color'),
	});
	WallLinkCustomMaterialProperty.prototype.getType = function (time) {
		return MaterialType;
	};
	WallLinkCustomMaterialProperty.prototype.getValue = function (time, result) {
		if (!defined(result)) {
			result = {};
		}
		result.color = Property.getValueOrClonedDefault(this._color, time, Color.WHITE, result.color);
		result.image = options.image;
		result.time = ((new Date().getTime() - this._time) % this.duration) / this.duration;
		return result;
	};
	WallLinkCustomMaterialProperty.prototype.equals = function (other) {
		return this === other || (other instanceof WallLinkCustomMaterialProperty && Property.equals(this._color, other._color));
	};
	//动态墙
	Material._materialCache.addMaterial(MaterialType, {
		fabric: {
			type: MaterialType,
			uniforms: {
				color: new Color(1.0, 0.0, 0.0, 0.5),
				image: options.image,
				time: 0,
			},
			source: _getDirectionWallShader({
				get: true,
				count: options.count,
				freely: options.freely,
				direction: options.direction,
			}),
		},
		translucent: function (material) {
			return true;
		},
	});

	return new WallLinkCustomMaterialProperty(options);
};

var _getDirectionWallShader = (options: any) => {
	if (options && options.get) {
		var materail =
			'czm_material czm_getMaterial(czm_materialInput materialInput)\n\
                    {\n\
                    czm_material material = czm_getDefaultMaterial(materialInput);\n\
                    vec2 st = materialInput.st;\n\
                    \n\ ';
		if (options.freely == 'vertical') {
			//（由下到上）

			materail += 'vec4 colorImage = texture2D(image, vec2(fract(float(' + options.count + ')*st.t ' + options.direction + ' time), fract(st.s)));\n\ ';
		} else {
			//（逆时针）

			materail += 'vec4 colorImage = texture2D(image, vec2(fract(float(' + options.count + ')*st.s ' + options.direction + ' time), fract(st.t)));\n\ ';
		}
		//泛光
		materail +=
			'vec4 fragColor;\n\
                    fragColor.rgb = (colorImage.rgb+color.rgb) / 1.0;\n\
                    fragColor = czm_gammaCorrect(fragColor);\n\ ';

		materail +=
			' material.diffuse = colorImage.rgb;\n\
                    material.alpha = colorImage.a;\n\
                    material.emission = fragColor.rgb;\n\
                    \n\
                    return material;\n\
                    }\n\
                    ';

		return materail;
	}
};

const drawing = ref(false);

// 电子围栏列表数据
const dataList: any = reactive([]);

// 电子围栏实体列表
var entities: any = [];

// 电子围栏point实体列表
var pointEntities: any = [];

// 当前选中实体索引
var geometryIndex: any = null;

/**
 * 点击绘制按钮
 */
const draw = () => {
	drawing.value = true;
};

/**
 * 点击表格一行
 */
const rowClick = (row: any, column: any, event: Event) => {
	if (column && column.property) {
		let index = dataList.findIndex((v: any) => v.id === row.id);
		if (index !== -1) {
			geometryIndex = index;
			props.viewer.flyTo(entities[index], flyOption);
		}
	}
};

/**
 * 删除已绘制的图形
 */
const delEntity = (item: any, index: number) => {
	props.viewer.entities.remove(entities[index]);
	entities.splice(index, 1);
	dataList.splice(index, 1);
};

/**
 * 点击确定绘制
 */
const submitForm = async (formEl: any) => {
	const valid = await formEl.validate();
	if (valid) {
		var pointList: any = [];
		pointEntities.forEach((entity: any) => {
			var { longitude, latitude } = getPosition(entity);
			pointList.push(longitude, latitude, form.height);
			props.viewer.entities.remove(entity);
		});
		var { longitude, latitude } = getPosition(pointEntities[0]);
		pointList.push(longitude, latitude, form.height);
		pointEntities = [];
		addElectronicFence(form.title, pointList);
		dialogFormVisible.value = false;
		formEl.resetFields();
	}
};

/**
 * 添加鼠标事件
 */
const addClickHandler = () => {
	handler = new Cesium.ScreenSpaceEventHandler(props.viewer.scene.canvas);
	// 单击绘制
	handler.setInputAction((event: any) => {
		leftClickHandler(event);
	}, Cesium.ScreenSpaceEventType.LEFT_CLICK);

	// 双击结束point绘制，开始围栏绘制
	handler.setInputAction((event: any) => {
		if (drawing.value) {
			drawing.value = false;
		}

		if (pointEntities.length) {
			dialogFormVisible.value = true;
		}
	}, Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
};

/**
 * 单击左键
 */
const leftClickHandler = debounce((event: any) => {
	if (drawing.value) {
		let cartesian = props.viewer.scene.pickPosition(event.position);
		let cartographic = Cesium.Cartographic.fromCartesian(cartesian);
		let coordinate = {
			longitude: Cesium.Math.toDegrees(cartographic.longitude),
			latitude: Cesium.Math.toDegrees(cartographic.latitude),
			height: cartographic.height + 1,
		};
		var pointGeometry = new Cesium.Entity({
			name: 'Sample Label',
			position: Cesium.Cartesian3.fromDegrees(coordinate.longitude, coordinate.latitude, coordinate.height),
			point: {
				// 实体是一个点
				pixelSize: 10, // 点的大小
				color: Cesium.Color.RED, // 点的颜色
			},
		});
		props.viewer.entities.add(pointGeometry);
		pointEntities.push(pointGeometry);
	}
}, 100);

/**
 * 获取实体的经纬度
 */
const getPosition = (entity: any) => {
	// 获取点实体的位置
	var position = entity.position.getValue(Cesium.JulianDate.now());
	// 转换Cartesian3到经纬度
	var cartographic = Cesium.Cartographic.fromCartesian(position, props.viewer.scene.globe.ellipsoid);
	var longitude = Cesium.Math.toDegrees(cartographic.longitude);
	var latitude = Cesium.Math.toDegrees(cartographic.latitude);
	return {
		longitude,
		latitude,
	};
};

onMounted(() => {
	addClickHandler();
});

onUnmounted(() => {
	entities.forEach((entity: any) => {
		props.viewer.entities.remove(entity);
	});
	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: 300px;
}
</style>