If you gesticulate while speaking, you may as well use those hand motions to design something at the same time. This is possible with a 3D drawing technique that combines hand motions and pen-based sketching.
In pursuit of improved 3D sketching tools, the researchers from the Korea Advanced Institute of Science and Technology (KAIST) developed the ILoveSketch 3D curve sketching system for professional designers. This was followed by SketchingWithHands for designing a handheld product with first-person hand postures captured by a hand-tracking sensor.
These investigations culminated in Agile 3D Sketching with Air Scaffolding, a new 3D sketching workflow 
The user makes unconstrained hand movements in the air to quickly generate rough shapes to be used as scaffolds. Source: KAISTcombining hand motion and pen drawing. The method enables designers to use hand motions in the air to create rough 3D shapes that will be used as scaffolds. Details can then be added with pen-based 3D sketching on a tablet.
The system employs an algorithm engineered to identify descriptive hand motions from transitory hand motions. Only intended shapes are extracted from unconstrained hand motions, based on air scaffolds from the identified motions.
The sketching technique was demonstrated to be simple to learn and use, and to reduce design time while enhancing the accuracy of defining the proportion and scale of products. Applications in the automobile, home appliances, animations and the movie making and robotics sectors are envisaged. Agile can also be used with smart production technology, such as 3D printing, to make manufacturing processes faster and more flexible.
