Updating glTF version for Cesium Ion tiled asset

Cesium ion
1

Whats the process to update a Cesium Ion asset tileset to glTF 2? Is there a way to do this without re-uploading the asset?

2

Hi Greg

We don’t have an option to upgrade to glTF 2 directly on Cesium ion.

A possible workaround - With the availability of the archive and exports feature, you can download/export the tileset and then run GitHub - CesiumGS/3d-tiles-tools to upgrade the tileset to glTF 2.0, and then reupload it to ion. This way, you don’t need to re-upload+re-tile the source, you’ll only be working with the tileset.

Shehzan

3

Thanks Shehzan, thats good to confirm. Might there be any performance or functionality advantages streaming glTF 2 tilesets with CesiumJS vs glTF 1?

Greg

4

Hi Greg

glTF 1 tilesets run through a fallback pipeline to convert glTF 1 → glTF 2 at runtime. So converting the assets to glTF 2 offline will mean less runtime overhead.

Shehzan

5

Thx again Shehzan. Is there a method to identify if a tileset is glTF ver 1 or 2? I’m working with tilesets generated by ContextCapture and had assumed they were glTF 2 but now thinking they are not.

Greg

6

Hi Greg

You can either do this by:

  1. loading it into the latest CesiumJS version which should put out console warnings.
  2. Opening any B3DM file in your tileset in a text editor and look for “version” in the glTF JSON text.

I believe ContextCapture output switched from glTF 1 to 2 in Version 16 or 17.

Shehzan