Bug Report - Unreal 4 Plugin - Can't save Overlay Material Layer Key

Hi there,

Thank you for taking time to read this email. We are using Ceisum plugin for UE4 to develop some map applications. It works great, however, recently we are facing a bug:

We are trying to blend different map tiles together so people can see some high res map tiles from our own data, and it works well with the material blend if we set up the correct Material Layer Key for different tilesets. The issue is whenever we save that map with the correct Material Layer key set up, and restart the project, it sets the Material Layer key back to default Overlay0.

Hope you guys can help with this issue.

Thank You.



Yushan Yin | Technical Artist | Polygon Labs™
39 W 38th St, 2W NY NY 10018 USA
+1 .973.515.0938 | polygonlabs.us

Hi Yushan,

Sorry to hear you’re having trouble! I have a few questions to get to the bottom of this issue.

What is the new Material Layer key that you are trying to set Overlay0 to? Are there any special characters, or spaces? My first guess is that there’s some character or string in the key that Unreal Editor doesn’t like.

Is the name of the layer in the Material Instance editor persisting as expected?

If you try applying a Cesium Polygon Raster Overlay with the same key to another tileset in the scene, does that key also get reset? Does it still occur if you remake the setup in a new map?


Hi Alex,

Thanks for the reply.

I am trying to set the Material Layer Key from Overlay0 to Overlay1, so I don’t think there are any special characters or spaces. It’s the same name as the layer in material needed.

So the other tile uses the Overlay0, we never need to change it, so I am not sure if it gets reset. I will try to reproduce it on a new map.


Hi Yushan,

Please let me know if the problem persists in other maps/projects - That name definitely shouldn’t be causing a problem, but I can’t replicate it on my end. If it doesn’t persist when you try the same thing in other projects, it may be a glitch with your Unreal project itself.

Also, just out of curiosity, what kind of overlay are you using on the tileset?