variety of computational simulations based on physical sand (see Figure 3). Users view these simulations as they are projected onto the surface of a sand model representing the terrain. They choose from a variety of simulations highlighting the height, slope, contours, shadows, drainage, or aspect of the landscape model.

Users alter the form of the landscape model by manipulating sand with their hands, seeing the resultant effects of computational analysis generated and projected onto the surface of the sand in real time. The project demonstrates how TUIs take advantage of our natural ability to understand and manipulate physical forms while harnessing the power of computational simulation to help us understand model representations. SandScape, which uses optical techniques to capture the geometry of a landscape model, is less accurate than its predecessor, Illuminating Clay, which used laser range finders to capture the geometry of a physical clay model [ 6].

SandScape and Illuminating Clay both demonstrate the potential advantage of combining physical and digital representations for landscape modeling and analysis. The physical clay and sand models convey spatial relationships that are intuitively and directly manipulated by hand. Users also insert any found physical objects directly under the camera. This approach allows them to quickly create and understand highly complex topographies that would be difficult and time-consuming to produce through conventional computer-aided design tools. This “ continuous and organic TUI” approach makes better use of our natural ability to discover solutions through direct manipulation of physical objects and materials.

 

CONCLUSION

TUIs give physical form to digital information and computation, facilitating the direct manipulation of bits. The goal is to empower collaboration, learning, and decision making through digital technology while taking advantage of our human ability to grasp and manipulate physical objects and materials. Here, I’ve introduced the genesis and evolution of TUIs over the past 10 years, from rigid discrete interface toward organic and malleable materials that enable dynamic sculpting and computational analysis using digitally augmented continuous physical materials. This new type of TUI delivers rapid form giving in combination with real-time computational feedback.

In addition to rapid form giving, actuation technology plays a critical role in making the interface more organic and dynamic. The Tangible Media Group is exploring the new genre of TUIs that incor-

porates actuation mechanisms to realize kinetic memory for educational toys like Curlybot [ 1] and Topobo [ 7]. It is also designing a new generation of tabletop TUIs that utilize actuation to make tangible objects behave more actively, dynamically representing the internal computational state; examples include the Actuated Workbench [ 4] and physical intervention in computational optimization, or PICO [ 5].

I hope the TUI evolution I’ve explored here will contribute to the future discussion of malleable, dynamic, organic interfaces that seamlessly integrate sensing and display into soft and hard digital/physical material. c

 

REFERENCES

1. Frei, P., Su, V., Mikhak, B., and Ishii, H. Curlybot: Designing a new class of computational toys. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (The Hague, The Netherlands, Apr. 1– 6). ACM Press, New York, 2000, 129–136.

2. Ishii, H., Ratti, C., Piper, B., Wang, Y., Biderman, A., and Ben-Joseph, E. Bringing clay and sand into digital design: Continuous tangible user interfaces. BT Technology Journal 22, 4 (2004), 287–299.

3. Ishii, H. and Ullmer, B. Tangible bits: Towards seamless interfaces between people, bits, and atoms. In Proceedings of the Conference on Human Factors in Computing Systems (Atlanta, Mar.). ACM Press, New York, 1997, 234–241.

4. Pangaro, G., Maynes-Aminzade, D., and Ishii, H. The Actuated Workbench: Computer-controlled actuation in tabletop tangible interfaces. In Proceedings of the 15th Annual ACM Symposium on User Interface Software and Technology (Paris, Oct. 27– 30). ACM Press, New York, 2002, 181–190.

5. Patten, J. and Ishii, H. Mechanical constraints as computational constraints in tabletop tangible interfaces. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (San Jose, CA, Apr. 28–May 3). ACM Press, New York, 2007, 809–818.

6. Piper, B., Ratti, C., and Ishii, H. Illuminating Clay: A 3D tangible interface for landscape analysis. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems: Changing Our World, Changing Ourselves (Minneapolis, Apr. 20– 25). ACM Press, New York, 2002, 355–362.

7. Raffle, H., Parkes, A., and Ishii, H. Topobo: A constructive assembly system with kinetic memory. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (Vienna, Apr. 24– 29). ACM Press, New York, 2004, 647–654.

8. Underkoffler, J. and Ishii, H. Urp: A luminous-tangible workbench for urban planning and design. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems: The CHI Is the Limit (May 15– 20). ACM Press, New York, 1999, 386–393.

9. Weiser, M. The computer for the 21st century. Scientific American 265, 3 (Sept. 1991), 94– 104.

 

HIROSHI ISHII ( [e-mail]) is the Muriel R. Cooper Professor of Media Arts and Sciences at the MIT Media Lab, Cambridge, MA, where he heads the Tangible Media Group and is co-director of the Things That Think consortium.

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