How to let czml packet to dispaly an object track in real time?

CesiumJS
1

Hi, All,
I'm going to display a car's track in real time. The car is moving and send back it's gps data. I want to display the car's track on Cesium. There are two issues.

1. I choose "range":"UNBOUNDED". Because "LOOP_STOP" always go back to the start point after ending. When clock crosses the end time, there is an exception throw out. Say,

DeveloperError: This object was destroyed, i.e., destroy() was called.
Error
    at new DeveloperError (http://192.168.1.105:8080/Source/Core/DeveloperError.js:37:17)
    at throwOnDestroyed (http://192.168.1.105:8080/Source/Core/destroyObject.js:44:19)
    at CompositePrimitive.update (http://192.168.1.105:8080/Source/Scene/CompositePrimitive.js:410:27)
    at updatePrimitives (http://192.168.1.105:8080/Source/Scene/Scene.js:828:27)
    at Scene.render (http://192.168.1.105:8080/Source/Scene/Scene.js:886:9)
    at CesiumWidget.render (http://192.168.1.105:8080/Source/Widgets/CesiumWidget/CesiumWidget.js:537:25)
    at Viewer.render (http://192.168.1.105:8080/Source/Widgets/Viewer/Viewer.js:701:28)
    at render (http://192.168.1.105:8080/Source/Widgets/Viewer/Viewer.js:69:28)

How to solve this exception?

2. I don't want to display the track ahead of my car. It's a real-time tracking system. So I cannot get "real" current position of the car, by the speed limit of light and network traffic delay. To fill this gap, I set the end time of every czml packet 30 second ahead of real time. Then there is always a 30 seconds line ahead of my car. How to remove such redundant line and let my model at the very head of the line.

Thanks,
Shawn

2

Hi Shawn,
   I was wondering if you ever got this working? Were you ever able to find any examples of how to do this? I am looking at doing something similar and am having a hard time finding any examples of how to accomplish it. Thanks.

Stephanie

3

Hi Shawn,

My project is like yours can you please share some examples.

I have to show flight data as they are flying in real time without reloading page. Multiple flights at a time.

If any one have done something similar please let me know with example.

Thanks
lg

4

Hi. Did you ever find any good examples of how to do this? I'm currently working on a project to display realtime flight trajectories but can't find any good examples how to deal with reltime datasource. I have used google maps before with periodic update interval to fetch new data (2d representation) but can't find any good examples in cesium.