CityGML to 3D Tiles - Misplaced when viewing in GIS

Cesium ion
1

Hi everyone,

i am currently trying out Cesium Ion to produce 3D-Tiles from CityGML Data.
At the moment i am encountering a problem, where i probably need help or explanation.

I am using CityGML Data from the state of Brandenburg (Germany)
https://data.geobasis-bb.de/geobasis/daten/3d_gebaeude/lod2_gml/

To be able to process the data in Ion, I make use of a very simple FME Reader - Writer Workflow to format the Data correctly for Cesium Ion (CityGML 2.0).

Cesium Ion processes the data sucessfully, but whenever i try to visualize the Data outside the Cesium Viewer (QGIS, ArcGIS, etc.) the tiles location is offset (sometimes stacked on top of each other) and the tiles height seems to be incorrect (see below). In the Cesium Viewer (online / localhost) everything is perfectly fine again.

Any idea, why what the cause for this misplacement/described behaviour is, or how i can visualize the 3D-Tiles in a GIS correctly?
If you need any further information, please let me know :slight_smile:

In the Cesium Viewer (correct location, correct heights):

Screenshot 2024-06-18 101053
Screenshot 2024-06-18 1010531124×580 66.5 KB

In QGIS (2D View) (Buildings location shifted south-east):

Screenshot 2024-06-18 101131
Screenshot 2024-06-18 101131797×804 170 KB

In QGIS (3D View) (Tile location shifted + heights wrong (rightside tile):

Screenshot 2024-06-18 101155
Screenshot 2024-06-18 1011551742×879 16.6 KB

2

Hi,

Can you please confirm if you are utilizing terrain clamping when uploading your CityGML models? Also please confirm how you are loading this data into QGIS?

Thanks,
Ankit

1 Like
3

Hi,

i tried with terrain clamping and without. The resulting positioning errors when visualizing in QGIS stay the same
(The visualization in the Cesium Viewer on the other hand change (object heights are clamped accordingly when using terrain clamping).

It also does not matter how i load the tiles into QGIS. The results are the same when i download the tileset from Ion and load the downloaded data into QGIS (drag and drop) and when i use the Cesium Ion QGIS Plugin to add the tilesets to a project.

5

Hi,

Would you be able to attempt to load NYC buildings or our newly released Japan 3D Buildings, which are both CityGML datasets, into QGIS to verify that they have the same positing issues?

This will help us narrow down if you are seeing the issue due to the tiler or the QGIS viewer and we can then help you with the appropriate steps.

Thanks,
Ankit