How to access archived tile maps on Android tablet


I am trying to test using downloaded data (imagery, elevation) in a Unity project deployed to an Android tablet. Basically I want to test using Cesium data on an Android tablet that has no wifi connectivity. I have followed the Cesium for Unity documentation including the section that relates to using data downloaded from the Ion account. Once the project is built on the tablet and I press play, none of the map data shows up.

Do you have any suggestions or further documentation?

Thank you,

Hi @shanereynolds,

Just so we can better understand your situation, can you tell us

  • where are you storing the downloaded data?
  • are you accessing it via the url option on the Cesium3DTileset component?

Hi Janine,

Thank you for getting back to me. Here is a general idea of the steps taken so far.

  1. Use GlobalMapper to download imagery and elevation data for an area.
  2. Import that data into Cesium Ion and select the “Make available for download” option
  3. Once data is processed by Cesium Ion, download the data
  4. In Unity project with Cesium plugin we use the URL field option
  5. The project is set to use the persistent data path so we don’t have permission issues on Android

From there we build and run the app. The map data does not show. Only if we connect to the internet at which point it is pulling the maps from Ion. The downloaded map data is being stored in the persistent path directory.

Do you have an example Unity project that is using downloaded “offline” map data than can run on Android?


Hi @shanereynolds,

I’m afraid that we don’t have an example of offline data being used in an app. I just want to clarify your process before I can determine if it’s a bug with Cesium for Unity:

EDIT: I didn’t read carefully that this is imagery data, so I rewrote some of these points:

  • You downloaded the data from ion, which gives you the data stored as local files on your computer.
  • You have a local URL to the files on your computer, and you put this URL into Unity
  • You are building and running the app on Android, and it works, but only if you are connected to the internet. In other words, it worked to begin with, but now it is being blocked by not having internet connection, despite being “offline.”

Does this all sound right to you?


It is actually both imagery and elevation data. But yes basically those are my steps. I think it works when on wifi because it is connection to Ion where I had originally uploaded the data. But yes, we are using the URL option and storing the data in an area where Android should not have any permission issues.

Are you able to try this process on your end?

Hi @shanereynolds,

I tried to reproduce the problem on my Windows machine, but I was still able to load local data just fine. So it must be either something with Android, or something with the application itself. Can you share a minimal reproducible example so that we can try and debug it?

Hi Janine,

I might be able to put something together. It works fine for us as well on Windows. But once the project is pushed to the Android device it no longer works. Where can I send the project?

  • Shane

Hi @shanereynolds,

You can email it to me directly at You can also upload the files to this post yourself, if it is small enough and doesn’t contain any sensitive data.