I have a web app which helps the user generate a 3D model. From teh web app, I have an "Upload to Shapeways" button at teh end of the creation process, but also a download the model button. I don't want the user to leave my web app to sign in to shapeways, so I'm opening a new popup with teh auth URL I get from the Shapeways OAuth service. Problem is I'm getting stuck in many ways and my limited brain could do with a good example or workflow of how to proceed. Is there a suitable example I could use? all the ones I've seen leave the app or require signing in first (which I really don't want). Thanks. Thomas