单个czml加载小车

 // 单个czml加载小车
        var scene = viewer.scene;
        var entity;
        var positionProperty;
        var clock = new Cesium.Clock({
            startTime: Cesium.JulianDate.fromIso8601("2012-08-04T16:00:00Z"),
            currentTime: Cesium.JulianDate.fromIso8601("2012-08-04T16:00:00Z"),
            stopTime: Cesium.JulianDate.fromIso8601("2012-08-04T16:03:00Z"),
            clockRange: Cesium.ClockRange.LOOP_STOP,
            clockStep: Cesium.ClockStep.SYSTEM_CLOCK_MULTIPLIER
        });
        var tileset = scene.primitives.add(
            new Cesium.Cesium3DTileset({
                url: 'http://192.168.1.1/3dmodel/3dtile/tileset.json'
            })
        );
        const czmlPath = "http://192.168.1.1/carModel/path/czmlPath.czml"
        var dataSourcePromise = Cesium.CzmlDataSource.load(czmlPath);
        var that = this;
        viewer.dataSources.add(dataSourcePromise, that).then(function (dataSource) {
            entity = dataSource.entities.getById('Vehicle');
            viewer.trackedEntity = entity;
            positionProperty = entity.position;
            if (positionProperty != undefined) {
                entity.orientation = new Cesium.VelocityOrientationProperty(positionProperty);
            }

        });

        if (scene.clampToHeightSupported) {
            tileset.initialTilesLoaded.addEventListener(start2);
        } else {
            console.log('This browser does not support clampToHeight.');
        }

        function start2() {
            var objectsToExclude = [entity];
            scene.postRender.addEventListener(function () {
                var position = positionProperty.getValue(viewer.clock.currentTime);
                if (position != undefined) {
                    entity.position = scene.clampToHeight(position, objectsToExclude);
                }
            });
        }
        // viewer.trackedEntity = entity;

设置视角

carEntity.viewFrom = new Cesium.Cartesian3(15, 15, 6);