by B.J. Novitski

From Brazil comes good news for anyone who has ever felt like they have one hand tied behind their back when manipulating 3D forms with a 2D drawing instrument.

University of Brasilia architecture professor Edison Pratini has been developing the "3D SketchMaker," which relies on natural, expressive hand gestures for creating 3D computer models. This process makes form-giving easier and removes the discontinuity between conceiving a form and translating it into a digital model.

Pratini wanted to produce this work because, he says, "pointing devices like computer mice and menus in existing software do not allow the freedom, quickness, and spontaneity needed to establish a continuous cycling of information between eye, brain, hand, and paper." He wanted to take advantage of the natural gestures most people use when describing the shape of objects.

His first prototype relies on a 3D mouse, data glove, or any sensor that transmits x,y,z data to the computer instead of the x,y data of a conventional mouse. The designer makes natural gestures in space to create two curves or lines. The software translates one curve into a sectional profile and the other into a path. Then it creates a surface model of that profile being extruded along the path. The resulting model can be further refined through normal 3D modeling software.

With Edison Pratini's first 3D SketchMaker prototype, a 3D mouse moving in space provides the data to shape a computer model. Photo and image: Edison Pratini The first gesture forms the sectional profile; the second specifies the path of extrusion. Image: Edison Pratini