1. A concise explanation of the problem you’re experiencing.
I have 100 GeoJsons. 100Mb each ( heigh data in a property). I need to convert them into czml so that I can display evolution of the 3d buildings over 100 years.
If I convert them in czml it would be several GB which is to big to display in a browser. What are the best practices ? can the czml bein splited in many small files which will be loaded based on the zoom level, location and time ?
CZML is not the correct format for what you want to do. I would recommend Cesium 3D Tiles which was designed for massive datasets like this (the end result will be much smaller than expect as well, a 16GB CityGML of every building in NYC is only ~220MB once converted to 3D Tiles with Draco compression). I would expect your 100 GeoJSON to shrink in a similar fashion.
Unfortunately, Cesium ion’s GeoJSON -> 3D Tiles converter is not available publicly yet (but we definitely want full drag and drop tiling support in ion). However depending on your data and use case, we still may be able to help you out. Contact tim@cesium.com with your details if you’re interested in discussing this further.
Otherwise, 3D Tiles is an open format, so you could potentially convert the data yourself: https://github.com/AnalyticalGraphicsInc/3d-tiles
Thanks,
Matt
thanks Matt. We’ll definitely look at the 3d-tiles specs. We want to do a 4D poc as that in the CZML demo page but with a lot of buildings. We’ve implemented it using MapBox (live demo https://geovation.github.io/changes-demo/) but it is not very good transitioning from time 1 to time 2 (it is not possible to know exactly when a layers has been fully displayed and therefore it is not possible to hide the previous layer at the right time provoking an ugly flicking). That’s why we are looking for an alternative that allows the 4th D: time.