In a 3D geology visualization concept application I worked on with David Wicks, the user needed a way to select which parts of the 3D model they wanted to see. I designed and implemented a gestural interface for selecting layers of the model by number entry, which was how users were accustomed to working with these models.
The application was made for a triptych of screens (or projectors), reflected in the mockups below by the wide aspect ratio.
Early on, we thought about the ergonomics of the gesture made. Human forearms are good at making arcs, not complete circles. Through informal user testing we also observed that people needed extensive verbal instruction to use the menu, so we adopted hand pose graphics in the interface to ease the UI's learning curve.
I implemented a functional prototype in the larger application.
We had to consolidate the different orthographic views into a single view due to technical constraints. We also added trays to display the currently selected layers, complete with a sub menu for removing layers.