Tiles not loading, crippled renders, tiles "popping" in & out

4 weeks into testing for a panoramic 3D stereo flight animation I am getting desparate. There´s a couple of things I just cannot get rid of, they seem to get worse every time I try:

  1. The tiles load excruciatingly slow, often I get an incomplete tile load in the editor, with large portions of the area missing

  2. Same happens in rendering, the more frames I render, the worse it becomes. After 300 images in the animation, all I get is “empty space”.

  3. Even with tiles loading., I get “popping in” effects in the background, or LOD´s flickering back and forth

My time for production is running out, so I am slowly staring to panic… any idea where I am doing things wrong??

Thanks for your help!!


Hi @MClostermann,

Sorry to hear you’re having trouble. We need more details in order to reproduce and then troubleshoot your issue.

  • What versions of Unreal Engine + Cesium for Unreal are you using?
  • What data are you using? Is it Cesium World Terrain, Google Photorealistic 3D Tiles, or your own dataset?
  • Please include a screenshot of your tileset settings.
  • Are you able to reproduce this issue in the Cesium for Unreal Samples project? If so, please give us step-by-step instructions for constructing your level and rendering your animation. This is the best way for us to accurately recreate your issue and fix it from there.

Thank you!

Dear Janine,

Thank you for getting back to me so quickly!

I use Unreal 5.3 and the 2.20 Cesium - the latest versions of everything. I made sure again that I have the latest versions installed this morning.
I use Google 3D tiles
Screenshots attached

I haven´t had the time to reproduce the whole Sh…t with the Cesium sample project yet. I’ll do that tomorrow morning. ( it is 8 pm here now) . But I have set up a fresh project this afternoon, thinking that I might have gone wrong somewhere in developing the other project. In the „Vienna flight“ project, I also deleted the complete tiles & Cesium in the Vienna final project and inserted a new one. Same result - less harsh ( like in the beginning) , but same problems…

If you want to, you can simply look at the project directly, it is no secret…:


Again, thanks for your help. I am really sweating here, despite the cold…


Looks like you’re rendering with a non-16:9 aspect ratio. Unreal Engine, frustratingly, does not provide any way for us to determine programmatically that this is the case under MRQ, so it causes tile selection bugs. The workaround is documented here: