Dust till Drawn A Real - time Bidirectional Pastel Simulation

We present a system for drawing pastel media in real-time as an effective alternative to most existing digital solutions that basically allow for drawing arbitrary strokes in a particular style. Our approach is focused on the simulation of the natural material itself and on its interaction with the drawing surface and the drawing tool. Upon free-form drawing, a bidirectional transfer of pigment takes place. In one direction, the paper surface is dusted with new pigment particles broken off the tip (i.e. the end of the drawing tool). A large part of these particles will be deposited or blended together with previously deposited ones whereas the remainder does not contribute to the drawing and is blown off. On the other hand, a certain amount of previously deposited pigment is scraped off and picked up again soiling the tip. This is noticeable in the next strokes to be drawn. Furthermore, both the tip and the paper surface are subject to weathering depending on the exerted pressure and friction of the drawing tool, and the bumpiness of the paper. As a result, the paper surface slightly gets damaged limiting the deposition of new pigment. The tip, on the other hand, becomes blunt making new strokes wider. From a stylistic point of view, similar to traditional drawings our results convey the artists’ characteristics (e.g., way of wielding the brush, skillfulness, feeling for the medium). Therefore, we believe our system allows an artist to create realistically looking pastel images without losing his/her personal touch. W. Van Haevre, T. Van Laerhoven, F. Di Fiore, F. Van Reeth Hasselt University Expertise Centre for Digital Media transnationale Universiteit Limburg Wetenschapspark, 2 BE-3590 Diepenbeek (Belgium) E-mail: [email protected] CR Subject Classification I.3.4 [Graphics Utilities] Paint Systems · I.3.6 [Methodology and Techniques] Interaction Techniques · I.3.M [Miscellaneous] Highly-stylized Drawn Images