Shape-It-Up is a novel interaction system for 3D modelling. The tool, which has been developed in the United States, enables you to create and modify both symmetric and asymmetric 3D shapes by using natural, intuitive hand gestures.

Shape-It-Up lets you Model 3D objects with hand gestures

Over the last few years, computer-based creation of objects and forms has made great progress as two-dimensional design has given way to designing – and printing – in three dimensions. Now four researchers at the C-Design Lab at Purdue University in Indiana have developed a means of creating 3D shapes which, instead of using the traditional man-machine, mouse-and-keyboard interface, integrates natural human hand gestures with a modelling scheme dubbed ‘intelligent generalised cylinders’ (IGC). The system focuses in particular on the initial creative stage, starting with cylindrical forms, which the user can then modify and refine in an iterative process.

A "hands-on" approach to design

The Shape-It-Up prototype uses a screen, a computer and an off-the shelf Microsoft Kinect camera, which captures the user’s movements, together with a new concept design programme called shape-gesture-context interplay (SGCI). As the C-Design Lab explains, the user starts by pointing both hands towards a screen to define the profile of the ‘object’, the cylinder. The user’s gestures then turn the profile into a 3D model in real time. Three basic modifications can then be executed. First, seizing the object with both hands allows the user to create ‘rotationally symmetric deformations’ on the 3D shapes; when the user releases the object the deformation stops automatically. Second, seizing the object with one hand and moving in space enables the symmetrical shape to be converted into a free-form asymmetrical shape. And lastly, by taking hold of the object at the top or bottom, the user can intuitively bend the shape.

From 3D shape to printer

The researchers foresee many potential applications of this system. Video games, architecture, art and engineering are the main fields where it could be used, as these are all areas which call for the building of asymmetric objects. The Shape-It-Up system offers great latitude when it comes to low-cost geometric object design, as the only equipment required apart from computer and screen is an off-the-shelf Kinect camera. At a later stage, the shapes which have been designed can be exported to a 3D printer and ‘printed’ out. This system has similarities with the eye-tracking project being worked on by a team from Cornell University, New York and the University of Wyoming in the United States in terms of the modelling concept, the difference being that there the aim is hands-free design.

By Guillaume Parodi