update：车案例的修改

src/examples/movingTarget/vehicle/vehicle-function.js

 export function addVehicle(viewer) {
-    const czml = [
-        {
-            id: "document",
-            name: "Vehicle",
-            version: "1.0",
-            clock: {
-                interval: "2019-08-28T04:00:00Z/2019-08-28T04:20:00Z",
-                currentTime: "2019-08-28T04:00:00.00Z",
-                multiplier: 1,
-                range: "LOOP_STOP",
-                step: "SYSTEM_CLOCK_MULTIPLIER"
-                }
-        },
-        {
-            id: "path",
-            name: "path for Vehicle",
-            description: "<p>this is a description</p>",
-            availability: "2019-08-28T04:00:00Z/2019-08-28T04:20:00Z",
-            path: {
-                material: {
-                    polylineOutline: {
-                        color: {
-                            rgba: [255, 0, 255, 255],
-                        },
-                        outlineColor: {
-                            rgba: [0, 255, 255, 255],
-                        },
-                        outlineWidth: 5    
-                    }, 
-                },
-                width: 8,   // 折线宽度
-                leadTime: 5,  
-                trailTime: 50000,
-                resolution: 5,
-                },
-                orientation: {
-                "velocityReference": "#position"
-                },
-                model: {
-                    gltf: 'https://raw.githubusercontent.com/jinlinchao123/Cesium-assets/main/3Dmodel/CesiumMilkTruck.glb',
-                    minimumPixelSize: 128,
-                },
-                position: {
-                    epoch: "2019-08-28T04:00:00.00Z",
-                    cartographicDegrees: [
-                        0, 120, 30, 0,
-                        1200, 121, 30, 0
-                    ]
-                }
-        },
+    // 定义开始时间
+    let start = Cesium.JulianDate.fromDate(new Date());  // 设置时间轴当前时间为开始时间
+    start = Cesium.JulianDate.addHours(start, 8, new Cesium.JulianDate());   // 开始时间加8小时改为北京时间
+    let stop = Cesium.JulianDate.addSeconds(start, 400, new Cesium.JulianDate());   // 设置结束时间为开始时间加400秒
+
+    viewer.clock.startTime = start.clone();  // 设置时钟开始时间
+    viewer.clock.currentTime = start.clone();  // 设置时钟当前时间
+    viewer.clock.stopTime = stop.clone();  // 设置时钟结束时间
+    viewer.clock.multiplier = 10;  // 设置时间倍数
+    viewer.timeline.zoomTo(start, stop);  // 时间轴绑定到viewer上去
+    viewer.clock.clockRange = Cesium.ClockRange.LOOP_STOP;  // 循环执行，到达终止时间，重新从起点时间开始
+
+    function computeFlight(source) {
+		var property = new Cesium.SampledPositionProperty();
+		for(var i = 0; i < source.length; i++) {
+			var time = Cesium.JulianDate.addSeconds(start, source[i].time, new Cesium.JulianDate ());
+			var position =Cesium.Cartesian3.fromDegrees(source[i].longitude, source[i].latitude, source[i].height);
+			property.addSample(time,position);
+		}
+		return property;
+	}   
+
+    let data = [
+        { longitude:108.95847801120208, latitude:34.21765422118126, height: -3.948, time: 0 },
+        { longitude:108.95849254781227, latitude:34.21800309998983, height: -3.839, time: 100 },
+        { longitude:108.9594164044393, latitude:34.21802855891169, height: -2.579, time: 200 },
     ];
 
-    var dataSourcePromise = viewer.dataSources.add(Cesium.CzmlDataSource.load(czml));
-    dataSourcePromise.then(function (dataSource) {
-        // 根据模型所在的实体去进行加载
-        viewer.trackedEntity = dataSource.entities.getById('path');
-    }).catch(function (error) {
-        console.error(error);
+    let property = computeFlight(data);              
+    // 添加模型
+    let entityCar = viewer.entities.add({
+        id: "car",
+        availability: new Cesium.TimeIntervalCollection([ //要添加到集合中的间隔数组
+            new Cesium.TimeInterval({start: start, stop: stop}),
+        ]),
+        position: property,
+        path: {
+            resolution: 1, 
+            leadTime: 0, 
+            trailTime: 200,
+            material: new Cesium.PolylineGlowMaterialProperty({
+                glowPower: 0.1,
+                color: Cesium.Color.ORANGE
+            }),
+            width: 10
+        },
+        orientation: new Cesium.VelocityOrientationProperty(property),  // 根据速度计算方向角
+        model: {
+            uri:'https://raw.githubusercontent.com/jinlinchao123/Cesium-assets/main/3Dmodel/CesiumMilkTruck.glb',
+            minimumPixelSize: 2,
+        }
     });
-}
+    viewer.trackedEntity = entityCar;   // 视角跟随模型
+}
\ No newline at end of file