A 3-dimensional modeling system inspired by the cognitive process of sketching

Abstract

Three-dimensional computer modeling software is becoming an increasingly important application to modern artists, designers, engineers, architects, and even laypersons. Where modeling applications were once extremely expensive and complex—available only to large businesses and institutions—recent advances in commodity computer hardware and the spread of consumer demand now places these applications within the reach of a much wider audience. Although commercial modeling applications are powerful, their interfaces are complex and unintuitive to artists and designers. Furthermore, most lack the ability to quickly create models in the early stages of design. The 3-D modeling and user interface research fields have begun to address these issues with sketch-based modeling interfaces, which purport to allow users to quickly sketch simple models, often combining modeling methods based on traditional physical artistic techniques, and utilizing drawing input from a digitizing tablet.

Sketch-based modeling research has made a great deal of progress. However a survey of current techniques reveals three reoccurring areas of oversight. (1) Most modeling interfaces attempt to mimic a specific artistic medium or technique—providing the user with an uneasy facsimile of the original, and the system with impoverished 3-dimensional input. (2) Many interfaces place too little consideration on the user’s necessarily 2-dimensional experience of the modeling process. And, (3) Projects that utilize a digitizing tablet focus only on positional input and ignore the rich source of additional dynamic physical pressure, hover, and tilt information provided by the tablet hardware.

To address these shortcomings, a sketch-based modeling prototype application and modeling interface were developed that focus on the cognitive aspect of the traditional sketching process, rather than on a specific technique. The system uses sketching strokes drawn onto user-adjustable 2-dimensional drawing surfaces within a 3-dimensional environment to quickly generate 3-D models through flexible and intuitive sweep and extrusion methods. The interface also features a number of novel tablet gestures that utilize dynamic physical information from a digitizing tablet to control the application with natural and intuitive gesticulations.

Preliminary assessment of the modeling methods suggests that the interface is effective for quick or preliminary modeling activities, and that some natural media related techniques may be required to properly address all areas of sketching technique. Furthermore, the system of tablet gestures is shown to be an intuitive and compelling channel of application control, and an exciting prospect for further research.