Regarding the processing of the model after the conclusion of the clock animation

CesiumJS
1

The animation is over, and the model will disappear or loop, but I want to achieve real-time vehicle trajectory playback. The animation playback is not continuous, and there may be delays. Therefore, during the waiting time for data, I want the model to still be displayed on the map. I don’t understand why the model needs to disappear when the animation ends.

const timeStepInSeconds = 30;
const totalSeconds = timeStepInSeconds * (flightData.length - 1);
const start = Cesium.JulianDate.fromIso8601(“2020-03-09T23:10:00Z”);
const stop = Cesium.JulianDate.fromIso8601(“2020-03-09T24:10:10Z”);
// Cesium.JulianDate.addSeconds(
// start,
// totalSeconds,
// new Cesium.JulianDate()
// );
viewer.clock.startTime = start.clone();
viewer.clock.stopTime = stop.clone();
viewer.clock.currentTime = start.clone();
viewer.timeline.zoomTo(start, stop);
// Speed up the playback speed 50x.
viewer.clock.multiplier = 1;
// Start playing the scene.
viewer.clock.shouldAnimate = true;
viewer.clock.clockRange = Cesium.ClockRange.CLAMPED;
// The SampledPositionedProperty stores the position and timestamp for each sample along the radar sample series.
const positionProperty = new Cesium.SampledPositionProperty();
for (let i = 0; i < flightData.length; i++) {
const dataPoint = flightData[i];
const time = Cesium.JulianDate.fromIso8601(dataPoint.time);
const position = Cesium.Cartesian3.fromDegrees(
dataPoint.longitude,
dataPoint.latitude,
dataPoint.height
);

      positionProperty.addSample(time, position);
      viewer.entities.add({
        description: `Location: (${dataPoint.longitude}, ${dataPoint.latitude}, ${dataPoint.height})`,
        position: position,
        point: { pixelSize: 10, color: Cesium.Color.BLUE },
      });
    }

  async function loadModel() {
    console.log("loadModel");
    console.log(Cesium.TimeInterval);
    // Load the glTF model from Cesium ion.
    const airplaneUri = await Cesium.IonResource.fromAssetId("2867724");
    const airplaneEntity = viewer.entities.add({
      availability: new Cesium.TimeIntervalCollection([
        {
          start: start.clone(),
          stop: stop.clone(),
        },
      ]),
      position: positionProperty,
      // Attach the 3D model instead of the green point.
      model: { uri: airplaneUri },
      // Automatically compute the orientation from the position.
      orientation: new Cesium.VelocityOrientationProperty(positionProperty),
      path: new Cesium.PathGraphics({ width: 3 }),
    });

    viewer.trackedEntity = airplaneEntity;
    viewer.camera.setView({
      destination: Cesium.Cartesian3.fromDegrees(-122.39053, 37.61779, 500),
    });
  }
  loadModel();