Implement 3D models from Cinema 4D

Hey guys,
I hope I am posting this in the right section.
For a project of my university I am building a webGL version of my university.
I am not bad in modelling with Cinema 4D, so I decided to do the modelling stuff there.
I didn’t really find out what types of 3D-models I can implement in WebGL, I read somewhere that I can only implement JSON files. It took me a while to get something that could get my C4D model thorugh XML to a JSON file, but now the created file seems invalid (says
Is there either a safe way to convert my models into JSON (I’m using “Altova XMLspy”) or maybe a way to implement other types of 3D models?
Thank you for your help,