How can i convert my ifc files into citygml files in order to visualize them on cesium globe?

General
2

I think one good way to do this is using FME, as mentioned here: Problem with uploading of CityGML to Cesium Ion - #3 by andre.

What software are you using to export the original IFC data? If you’re using something like Revit, you should be able to export it as FBX, which can be uploaded to Cesium ion and visualized in your app.