# Time availability for 3D tiles

**URL:** <https://community.cesium.com/t/time-availability-for-3d-tiles/9037>\
**Category:** CesiumJS\
**Created:** [January 30, 2020, 3:45pm UTC](https://community.cesium.com/t/time-availability-for-3d-tiles/9037 "2020-01-30T15:45:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Brian\_Ellingson](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@Brian\_Ellingson](https://community.cesium.com/u/Brian_Ellingson)\
**Post date:** [January 30, 2020, 3:45pm UTC](https://community.cesium.com/t/time-availability-for-3d-tiles/9037/1 "2020-01-30T15:45:38Z")

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Hi everyone! I opened a pull request a while ago, and I’d love to get some additional feedback on it.

[https://github.com/AnalyticalGraphicsInc/cesium/pull/8488](https://github.com/AnalyticalGraphicsInc/cesium/pull/8488)

I added an optional field in the tileset.json file that allows the user to specify an availability window per tile. If the current time is outside of a tile’s availability it will be excluded from the selectedTiles array. This is a helpful feature for those making animations by reapplying styles ([https://cesium.com/blog/2018/11/08/weather-prediction-data-time-series-and-3d-tiles/](https://cesium.com/blog/2018/11/08/weather-prediction-data-time-series-and-3d-tiles/)) as the clock time changes because the style is only applied to the tiles in the selectedTiles array, yielding a substantial performance gain with very large or dense datasets. The usecase that drove this is visualizing high density airborne radar data. I have a link to an example in the pull request for anyone interested to see the application. It shows data collected by HIWRAP aboard NASA’s ER2 during the OLYMPEX campaign ([https://ghrc.nsstc.nasa.gov/hydro/details/gpmhiwrapolyx](https://ghrc.nsstc.nasa.gov/hydro/details/gpmhiwrapolyx)).

Some of the benefits of this over the existing TimeDynamicPointCloud are (I use “frame” to refer to the content being displayed in a given instance of time):

- You can further organize your frames by levels of resolution.
- You don’t need to duplicate points across frames if it lingers longer than the time difference between frames.
- You can add time dynamics to existing tilesets by simply modifying tileset.json.
- This allows for time dynamics for tile types other than point cloud.

I’ve really enjoyed using Cesium, and I hope that my small modification can be useful for other developers too.

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**Author:** ![omar](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/omar/32/1999_2.png) [@omar](https://community.cesium.com/u/omar)\
**Post date:** [February 3, 2020, 9:03pm UTC](https://community.cesium.com/t/time-availability-for-3d-tiles/9037/2 "2020-02-03T21:03:25Z")

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Thanks for sharing this here Brian!

It’s really cool reading about the larger context this project was created in. Hopefully we can get someone to look at that PR soon!