ScaffoldSketch: Accurate Industrial Design Drawing in VR

We present an approach to in-air design drawing based on the two-stage approach common in 2D design drawing practice. The primary challenge to 3D drawing in-air is the accuracy of users’ strokes. Beautifying or auto-correcting an arbitrary drawing in 2D or 3D is challenging due to ambiguities stemming from many possible interpretations of a stroke. A similar challenge appears when drawing freehand on paper in the real world. 2D design drawing practice (as taught in industrial design school) addresses this by decomposing the process of creating realistic 2D projections of 3D shapes. Designers first create scaffold or construction lines. When drawing shape or structure curves, designers are guided by the scaffolds. Our key insight is that accurate industrial design drawing in 3D becomes tractable when decomposed into auto-correcting scaffold strokes, which have simple relationships with one another, followed by auto-correcting shape strokes with respect to the scaffold strokes. We demonstrate our approach’s effectiveness with an expert study involving industrial designers.