I3dm transformation and textures

Hi,

I’m trying out the new i3dm support in Cesium for Unreal, but there are a couple of serious problems with my instanced trees in the 3D Tiles dataset linked below:

image

  1. The trees are incorrectly rotated and below ground. The differences in rotation between the trees seem almost random as well.

  2. The tree textures are not found. The i3dm files are located in the “0” folder, referring glb files in the root folder above (which seems to work). The glb files are in turn referring the tree texture files in the same root folder, but here they are searched for in the “0” folder. If there will be several folders with i3dm files I wouldn’t want to duplicate the textures. I have tried referring the textures without any path from the glb files, and as here with “./” as prefix, but the only thing that works is to copy the texture files into the “0” folder.

All of this works fine in Cesium ION. Are these known issues?

I’m using UE 5.3.2 but I’m confused by the version of the Cesium for Unreal plugin. On Marketplace it says “This is Cesium for Unreal v2.5.0, published 2024-05-01.” and the linked changelog only goes to 2.5. But when checking Engine/Plugins/Marketplace/CesiumForUnreal/Changed.md it seems that 2.6 is actually installed. Am I using the latest release or not?

/Andreas

Hi @AndreasRemograph,

Thanks for reporting this error, and for including the image and dataset in your post. We’re going to look into this soon, and we’ll be sure to update this thread with what we find.

On Marketplace it says “This is Cesium for Unreal v2.5.0, published 2024-05-01.” and the linked changelog only goes to 2.5. But when checking Engine/Plugins/Marketplace/CesiumForUnreal/Changed.md it seems that 2.6 is actually installed. Am I using the latest release or not?

It sounds like you’re using the correct release, yes. I realized we never updated the description, so I’ve changed that to avoid confusion. Thank you for letting us know!

Hi @AndreasRemograph ,
Thanks for the detailed report and especially for the sample data.

I’ve opened i3dm conversion does not handle gltfUpAxis properly · Issue #904 · CesiumGS/cesium-native · GitHub and relative image paths in i3dm content are not resolved in the proper directory · Issue #905 · CesiumGS/cesium-native · GitHub to track these bugs.

  • Tim