Natural Interaction and Computer Graphics Applications

Abstract: Natural Interaction with computers has been a challenging topic of research since the very beginning of the digital era and refers to the possibility, on the user’s part, of exploiting natural abilities to control the machine and interpret its outputs. If in the infancy of computer graphics this meant using visual representation and pen pointing, nowadays more refined techniques are needed to fit the wide range of applications, from home entertainment to virtual and augmented reality. This paper describes some advances in gesture, tangible and surface computing, showing how such interaction models, if treated as a continuum, improve the usability, accessibility and overall experience of computer graphics applications.

Authors: S. A. Iacolina, A. Lai, A. Soro, R. Scateni.
Natural Interaction and Computer Graphics Applications.
EuroGraphics Italian Chapter 2010, 141-146.
Genova, Italia, Novembre 2010.

Tools and Applications for Teaching and Research in Computer Graphics.

Abstract: In this paper we present the work in progress along with some preliminary research results in the field of Computational Geometry and Mesh Processing obtained by the Computer Graphics Group of the University of Cagliari, Italy. We focus on the work in mesh analysis by introducing the development of a lightweight visualization and processing tool that helped expanding the aims of the group by letting the students from the University move their first steps in Computer Graphics. We show some results obtained by the group with the focus on the usefulness of a common framework of reference.

Authors: F. Guggeri, M. Livesu, R. Scateni.
Tools and Applications for Teaching and Research in Computer Graphics.
EuroGraphics Italian Chapter 2010, 147-152.
Genova, Italia, Novembre 2010.

Two examples of GPGPU acceleration of memory-intensive algorithm.

Abstract: The advent of GPGPU technologies has allowed for sensible speed-ups in many high-dimension, memory-intensive computational problems. In this paper we demonstrate the effectiveness of such techniques by describing two applications of GPGPU computing to two different subfields of computer graphics, namely computer vision and mesh processing. In the first case, CUDA technology is employed to accelerate the computation of approximation of motion between two images, known also as optical flow. As for mesh processing, we exploit the massively parallel architecture of CUDA devices to accelerate the face clustering procedure that is employed in many recent mesh segmentation algorithms. In both cases, the results obtained so far are presented and thoroughly discussed, along with the expected future development of the work.

Authors: S. Marras, C. Mura, E. Gobbetti, R. Scateni, R. Scopigno.
Two examples of GPGPU acceleration of memory-intensive algorithm.
EuroGraphics Italian Chapter 2010, 49-56.
Genova, Italia, Novembre 2010.

Interactive Calibration of a Multi-Projector System in a Video-Wall Multi-Touch Environment.

Abstract: Wall-sized interactive displays gain more and more attention as a valuable tool for multiuser applications, but typically require the adoption of projectors tiles. Projectors tend to display deformed images, due to lens distortion and/or imperfection, and because they are almost never perfectly aligned to the projection surface. Multi-projector videowalls are typically bounded to the video architecture and to the specific application to be displayed. This makes it harder to develop interactive applications, in which a fine grained control of the coordinate transformations (to and from user space and model space) is required. This paper presents a solution to such issues: implementing the blending functionalities at an application level allows seamless development of multi-display interactive applications with multi-touch capabilities. The description of the multi-touch interaction, guaranteed by an array of cameras on the baseline of the wall, is beyond the scope of this work which focuses on calibration.

Authors: A. Lai, A. Soro, R. Scateni.
Interactive Calibration of a Multi-Projector System in a Video-Wall Multi-Touch Environment.
UIST 2010 Adjunct Proceedings, 437-438.
New York, NY, USA, Ottobre 2010.

Fast Approximation of the Shape Diameter Function.

Abstract: In this paper we propose an optimization of the Shape Diameter Function (SDF) that we call Accelerated SDF (ASDF). We discuss in detail the advantages and disadvantages of the original SDF definition, proposing theoretical and practical approaches for speedup and approximation. Using Poisson-based interpolation we compute the SDF value for a small subset of randomly distributed faces and propagate the values over the mesh. We show the results obtained with ASDF versus SDF in terms of timings and error.

Authors: M. Kovacic, F. Guggeri, S. Marras, R. Scateni.
Fast Approximation of the Shape Diameter Function.
GraVisMa 2010, 65-72.
Brno, Rep. Ceca, Settembre 2010.