UTM Glb tiles in CesiumJS

Hi all!

I am currently working on a project where i try to visualize a glb file using CesiumJS within an html file.
As metioned the coordinates of the .glb file are in the UTM system. Is there a way to visualize the UTM glb with CesiumJS without transforming the .glb itself? The bounding volume region in the tilesetroot.json is in WGS84 (radians + meter). Do i need a transformation in the json or is there no way to visualize an UTM glb?

Thank you very much!

Hi @roots, thanks for the question! I think you will likely get a better answer from the 3D Tiles team so we’re going to transfer this thread over.

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It is not entirely clear for me where exactly the coordinate system comes into play here.

GLB/glTF has coordinate systems that are strictly specified, e.g. with ‘Y’ being the up-axis, and all units being in meters. This convention is independent of where on the globe that object should be displayed.

Within 3D Tiles, each tile can have a transform (a 16 element array representing a 4x4 matrix in column-major order). So the actual “placement” in the geospatial context can be accomplished with that.

(The bounding volumes in the 3D Tiles JSON can be regions that are defined in WGS84, but they can also be oriented bounding boxes that do not explicitly rely on the geospatial context).

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