Hi Everyone - Thanks for sharing this and this looks very nice.
While Cesium ion lets you upload your own data for tiling and streaming, I wanted to add a friendly reminder that Google’s terms of service are generally prohibit loading Google’s data into other products (thats why we can’t add Google Maps to CesiumJS and Cesium for Unreal for example). Google has a blanket ban on loading Google Maps data into non-Maps products (see Google maps instead of Bing maps please - #2 by Shehzan_Mohammed).
I am not a lawyer, so I would recommend that you to please check with your teams about your usage of Google’s data to make sure you are using the data and service within the terms of service.
Shehzan