Abstract: We present here a system built around the idea of giving to several users the possibility to interact with a cheap and solid hardware, at the same time, using natural gestures supported by an intuitive user interface. A projector and a camera are placed underneath a Plexiglas sheet, framed with an array of infrared LEDs, all set into a wooden table box. This allows for multiple users (up to four or five) to freely move around the box and manipulate the objects retro-projected on the screen, using a tangible interface designed aiming at offering few simple operations: geometric transforms (rotations, translations and scales), drawing, erasing and color selections. All of these are executed through the use of either a custom built IR LED pen and/or directly the fingers. The main purpose of the project is to offer an instrument of tangible interaction to classrooms of naive users (i.e.: neither technology nor science professors and students) in a university environment.
Authors: D. Cabiddu, G. Marcias, A. Soro, R. Scateni.
Multi-touch and Tangible Interface: Two Different Interaction Modes in the Same System.
ACM SIGCHI Italian Chapter (CHItaly 2011) Adjunct Proceedings (poster).
Alghero, Italia, Settembre 2011.
Abstract: We report on two interactive systems for natural exploration of 3D models. Manipulation and navigation of 3D virtual objects can be a difficult task for a novel user, specially with a common 2D display. With traditional input devices such as 3D mice, trackballs, etc. the interaction doesn’t insist directly on the models, but is mediated and not intuitive. Our user interface allows casual users to inspect 3D objects at various scales, panning, rotating, and zooming, all through hand manipulations analogous to the way people interact with the real world. We show the design and compare the tests on two alternative natural interfaces: multitouch and free-hand gestures. Both provide a natural dual-handed interaction and at the same time free the user from the need of adopting a separate device.
Abstract: Frustrated Total Internal Reflection (FTIR) is a key technology for the design of multi-touch systems. With respect to other solutions, such as Diffused Illumination (DI) and Diffused Surface Illumination (DSI), FTIR based sensors suffer less from ambient IR noise, and is, thus, more robust to variable lighting conditions. However, FTIR does not provide (or is weak on) some desirable features, such as finger proximity and tracking quick gestures. This paper presents an improvement for FTIR based multi-touch sensing that partly addresses the above issues exploiting the shadows projected on the surface by the hands to improve the quality of the tracking system. The proposed solution exploits natural uncontrolled light to improve the tracking algorithm: it takes advantage of the natural IR noise to aid tracking, thus turning one of the main issues of MT sensors into a useful quality, making it possible to implement pre-contact feedback and enhance tracking precision.