Supplementary Material


A wireframe chair drawn with scaffolds lines and shape strokes. There are four subfigures. The first shows the user input scaffold lines. The lines are drawn inaccurately. They loosely follow the edges of a box with additional lines dividing the box into regions, but they don't meet precisely at their ends. The second shows the auto-corrected scaffold lines, which do meet precisely and form a box with precise divisions. The third figure shows the user's drawn curves outlining the shape of a chair. The curves are wobbly. The fourth figure shows the auto-corrected curves, which are extremely smooth and meet precisely. ScaffoldSketch user inputs and system outputs. (a) The scaffold strokes a user drew in VR. (b) The auto-corrected scaffold from the user’s strokes. (c) The shape strokes the user drew in VR. (d) The auto-corrected shape from the user’s strokes and the scaffold.


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.

Video Overview (30 second)

Download as:

Video Figure (4 minutes)

Download as:

Presentation (7 minutes)

Download as:



 author    = {Yu, Xue and DiVerdi, Stephen and Sharma, Akshay and Gingold, Yotam},
 title     = {{S}caffold{S}ketch: Accurate Industrial Design Drawing in VR},
 booktitle = {Proceedings of ACM Symposium on User Interface Software and Technology},
 series    = {UIST},
 year      = {2021},
 keywords  = {industrial design, virtual reality, sketching, auto-correct}