Designing a 3D modelling tool for novice users

We present our design exploration for re-thinking underlying principles of 3D modelling activity on multi-touch tablets for novice users, identifying some of usability problems that often hinder the user interaction. We introduce "1.2 hand input," a specific interaction technique that helps novice users to gain understanding and orientation in interacting with 3D space on a 2D screen, and we derive multiple UI artefacts and techniques that take advantage of the particular characteristics afforded by this technique: a clear separation between the actions of modelling an object and of changing the viewpoint, a reduction of hand occlusion while performing multi-touch interactions by extending the touchable areas around the object model, and an improved access to the user's action history by combining the concept of viewpoint change with past interaction sequences re-shaping how traditionally the undo and redo actions have been done in the modelling activity.