Fatal Error when adding water material

Cesium for Unreal
1

Hi,

When using Cesium for Unreal with my own 3d tile data set, Unreal Engine 5.1 crashes when trying to add a water material and gives me this error;

Fatal error: [File:D:\build++UE5\Sync\Engine\Source\Runtime\TypedElementFramework\Public\Elements\Framework\TypedElementData.h] [Line: 276] Element ‘CesiumGltfPrimitiveComponent /Game/Machloop.Machloop:PersistentLevel.Cesium3DTileset_0.None.None - ID: 38’ is still externally referenced when being destroyed! Ref-count: 3; see above for reference information (if available).

Is there something I’m doing wrong?

Thanks for the help.

2

Hi @SimonLation,

Can you give us some more details so we can try to identify the error? These would help greatly:

  • What Cesium for Unreal version you’re using
  • What OS you’re using
  • Whether you can reproduce this in a Cesium for Unreal Samples level
  • What the material you’re using looks like – are there any notable qualities about it? (e.g. alpha / transparency, any additional material layers)
3

Hi,

  • What Cesium for Unreal version you’re using
    I am using Cesium for Unreal version 1.30.1

  • What OS you’re using
    I am on Windows 10

  • Whether you can reproduce this in a Cesium for Unreal Samples level
    I have tried this on the Cesium samples and get the same error.

  • What the material you’re using looks like – are there any notable qualities about it? (e.g. alpha / transparency, any additional material layers)
    The material I am using is the M_Water material that comes with Unreal Engine 5.1, so it’s a translucent shader with colour, roughness and a normal layer.

From further testing it seems to be that if I have a tile selected and then move it off of the viewport view it is what is actually causing the crash.

If I don’t select any tiles I can move around as normal, but as soon as I have a tile selected and it moves from view, that is when I get the crash happens. This also happens on the Cesium samples project too. I now believe the adding of the material is irrelevant and not actually causing the crash. I hadn’t changed anything in the sample scene and the crash still happens.

Thanks.

4

Hi @SimonLation,

Thank you for the additional information. Unfortunately I am not experiencing that crash in the Cesium for Unreal Samples with the same setup. To clarify, when you say you “have a tile selected”, do you mean you’re selecting the entire 3D Tileset? Or are you somehow selecting an individual tile in the 3D Tileset?

Could you also let me know which sample level(s) you’re able to trigger the crash on, so that I can reproduce the scenario one-for-one?

5

Hi

Yes I am selecting an individual tile.

The sample level I tested with was Melbourne.

6

Hi @SimonLation,

Thanks for the quick response. I was able to reproduce this crash, and I’ve written up an issue for it on Github here. We’ll investigate it further and update this forum thread when there’s progress.

1 Like
7

Hi @SimonLation,

We just merged a Github PR to fix this issue, and it will ship with the next release. Thanks for reporting this bug to us!

1 Like
8

Hi @janine,

Thanks for the update, I’ve marked your post as the solution so people will know his will now be fixed.

1 Like