# How to let czml packet to dispaly an object track in real time? **URL:** \ **Category:** CesiumJS\ **Created:** [January 15, 2014, 3:54pm UTC](https://community.cesium.com/t/how-to-let-czml-packet-to-dispaly-an-object-track-in-real-time/934 "2014-01-15T15:54:04Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![researcher\_pim](https://avatars.discourse-cdn.com/v4/letter/r/91b2a8/32.png) [@researcher\_pim](https://community.cesium.com/u/researcher_pim)\ **Post date:** [January 15, 2014, 3:54pm UTC](https://community.cesium.com/t/how-to-let-czml-packet-to-dispaly-an-object-track-in-real-time/934/1 "2014-01-15T15:54:04Z")
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](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](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](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](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](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](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](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](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 ---
**Author:** ![Stephanie\_Stites](https://avatars.discourse-cdn.com/v4/letter/s/ecb155/32.png) [@Stephanie\_Stites](https://community.cesium.com/u/Stephanie_Stites)\ **Post date:** [May 14, 2014, 7:11pm UTC](https://community.cesium.com/t/how-to-let-czml-packet-to-dispaly-an-object-track-in-real-time/934/2 "2014-05-14T19:11:36Z")
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 ---
**Author:** ![lgsoftwares](https://avatars.discourse-cdn.com/v4/letter/l/8dc957/32.png) [@lgsoftwares](https://community.cesium.com/u/lgsoftwares)\ **Post date:** [December 15, 2015, 2:57am UTC](https://community.cesium.com/t/how-to-let-czml-packet-to-dispaly-an-object-track-in-real-time/934/3 "2015-12-15T02:57:30Z")
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 ---
**Author:** ![mcslindh](https://avatars.discourse-cdn.com/v4/letter/m/e19adc/32.png) [@mcslindh](https://community.cesium.com/u/mcslindh)\ **Post date:** [June 3, 2016, 8:37am UTC](https://community.cesium.com/t/how-to-let-czml-packet-to-dispaly-an-object-track-in-real-time/934/4 "2016-06-03T08:37:54Z")
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.