Where to look to learn how to build Interactive Touchscreen Displays? in 4-20

I couldn’t figure out to edit the original post a second time.

It seems like I might be able to create the text overlays by thinking about it as a HUD?

But for the 3D elements, is there a way to lock that camera in a single position, so that touch commands could be used to rotate an object on screen? Or am I thinking of that backward and I should be using the camera to orbit around an object on screen? For instance, if I had an earth sphere and wanted to spin it around, should the commands move the sphere or the camera?