Collaborators: Thomas Jung, Ellen Yi-Luen Do
2004 AAAI Sketching in 3D is a useful way to access knowledge-based design systems. In this paper we present a framework for sketch-based interaction with intelligent systems in three-dimensional domains. The Space Pen software written in Java 3D is a platform to implement two architectural lighting design tools, Space Pen and Spot. Space Pen supports user annotations in the form of sketching, virtual post-it notes, and sketch object insertions. Spot supports access to direct simulation and visualization in a selected time period with sketching in 3D space. Light Pen suggests placement of lamps to light an intended area in space. In these examples, the 3D sketching front-end serves as an interface to a backend knowledge-based system. The designer can pose problems by drawing onto a 3D model to which knowledge-based systems offer a solution by either providing quantitative data analysis or modifying the 3-D model. The specific domain of architectural lighting is implemented, it exemplifies a more general class of 3-D pen-based interaction with intelligent systems.
2002 CHI EA: Collaborative design review is an important part of architectural design work. The Space Pen system supports annotation and drawing on (and inside) 3D VRML/Java models using a regular Web browser to exchange text and sketched annotations for review.
2002 IUI: This paper reports on our progress and findings in building a Web annotation system for non-immersive 3D virtual environments. Over the last two years, we developed and tested two systems for collaborating designers to comment on virtual 3D models. Our first system, Redliner  lets design team members browse and leave text annotations on surfaces in three-dimensional models. Experience with Redliner, including two user evaluations in different settings, led us to develop Space Pen , a second annotation system with improved interaction capabilities. It goes beyond the post-it note metaphor, allowing users to draw in and on the virtual environment.
2001 Designing a building or a new urban space is collaborative work that involves several people with different backgrounds. To achieve consensus all participants in the process meet to discuss documents such as floor plans and sections. This paper reports on the progress of Space Pen, a new system to allow several users to draw on and annotate a three-dimensional representation of a building remotely over the Internet.
2004 As if You Were Here – Intelligent Annotation in Space: 3D Sketching as an Interface to Knowledge Based Systems, E. Y-L. Do, M. Gross, American Association for Artificial Intelligence (AAAI), Fall Symposium Oct 22-24 [pdf]
2002 Sketching Annotations in 3D on the Web T. Jung, E. Do, and M. Gross, ACM Conference on Human Factors (SIGCHI), ACM Press, pp. 618-619 [pdf]
2002 Annotating and Sketching on 3D Web Models, T. Jung, E. Do, and M. Gross, ACM Intelligent User Interfaces 2002, San Francisco, Jan 13-16, ACM Press, pp 95-102. [pdf]
2001 Space Pen. Annotation and sketching on 3D models on the Internet. Jung, T., Mark Gross, and Ellen Yi-Luen Do, in Computer Aided Architectural Design Futures 2001: Proceedings of the Ninth International Conference held at the Eindhoven University of Technology, 257-270. CAAD Futures. Dordrecht: Kluwer Academic Publishers, 2001. [pdf]