PhantomPen: virtualization of pen head for digital drawing free from pen occlusion & visual parallax

Abstract

We present PhantomPen, a direct pen input device whose pen head is virtualized onto the tablet display surface and visually connected to a graspable pen barrel in order to achieve digital drawing free from pen occlusion and visual parallax. As the pen barrel approaches the display, the virtual pen head smoothly appears as if the rendered virtual pen head and the physical pen barrel are in unity. The virtual pen head provides visual feedback by changing its virtual form according to pen type, color, and thickness while the physical pen tip, hidden in the user's sight, provides tactile feedback. Three experiments were carefully designed based on an analysis of drawings by design professionals and observations of design drawing classes. With these experiments that simulate natural drawing we proved significant performance advantages of PhantomPen. PhantomPen was at least as usable as the normal stylus in basic line drawing, and was 17 % faster in focus region drawing (26% faster in extreme focus region drawing). PhantomPen also reduced error rate by 40 % in a typical drawing setup where users have to manage a complex combination of pen and stroke properties.