How tile exchange high level to low level and low to high?


To meet the requirements of the scenario, I need to know the method how different level tile exchange.
I read the source of Cesium, but finally almost give up, it was so complicated .
I found the _createTileImagerySkeletons , getImageryFromCache , removeImageryFromCache method, but how tile exchange or replace ?

Any help thank u!

Can you describe a bit more what you’re trying to do? CesiumJS loads higher resolution tiles based on the defined screen space error:

If you’re trying to be notified every time a new tile has loaded, you can listen on the tileLoadProgressEvent:

Thanks for u patience. I use the provider like ArcGisMapServerImageryProvider, and through the requestImge method to listen the tile (x, y, level) and get image, then use the image as Textured Material to 3d tiles or terrian (entity). I’m on the wrong track? Is there a better way? When I use the provider different level have different tiles and how to exchange or replace?

The Classification types examples:

Is your goal to display imagery on top of 3D Tiles? If so, this isn’t currently supported in CesiumJS, but we have a feature request for that here:

You can drape your imagery over your 3D terrain if you load it as a terrain provider in CesiumJS. What source format is your terrain in? If it’s a GeoTIFF you can upload that to Cesium ion (

yes. I subscribed the issue. Hope the new featrue would be come true. Thank u