Towards intelligent interfaces 

Before jumping into how, let's quickly discuss the why in order to motivate us as well as encourage creative exploration of this concept. As alluded to in the introduction, the first motivator is to reduce friction. Consider the soft keyboard (keyboard with no physical buttons) on your phone; due to the constraints of the medium, such as lack of space and feedback, inputting text without predictive text would be cumbersome to the point of rendering it unusable. Similarly, despite the convenience of drawing with our fingers, our fingers are not that accurate, which makes things difficult to draw.

The other reason why this concept (augmentation) is advantageous is its ability to democratize the technical skill of drawing. It's common for people to not even attempt to draw because they have convinced themselves that it is beyond their abilities, or possibly that we can enhance one's ability to draw. This was the motivation behind the research project ShadowDraw...