0000000000670635
AUTHOR
Stefano Papetti
To “Sketch-a-Scratch”
A surface can be harsh and raspy, or smooth and silky, and everything in between. We are used to sense these features with our fingertips as well as with our eyes and ears: the exploration of a surface is a multisensory experience. Tools, too, are often employed in the interaction with surfaces, since they augment our manipulation capabilities. “Sketch-a-Scratch” is a tool for the multisensory exploration and sketching of surface textures. The user’s actions drive a physical sound model of real materials’ response to interactions such as scraping, rubbing or rolling. Moreover, different input signals can be converted into 2D visual surface profiles, thus enabling to experience them visually…
Numerical methods for a nonlinear impact model: A comparative study with closed-form corrections
A physically based impact model-already known and exploited in the field of sound synthesis-is studied using both analytical tools and numerical simulations. It is shown that the Hamiltonian of a physical system composed of a mass impacting on a wall can be expressed analytically as a function of the mass velocity during contact. Moreover, an efficient and accurate approximation for the mass outbound velocity is presented, which allows to estimate the Hamiltonian at the end of the contact. Analytical results are then compared to numerical simulations obtained by discretizing the system with several numerical methods. It is shown that, for some regions of the parameter space, the trajectorie…
Multisensory texture exploration at the tip of the pen
A tool for the multisensory stylus-based exploration of virtual textures was used to investigate how different feedback modalities (static or dynamically deformed images, vibration, sound) affect exploratory gestures. To this end, we ran an experiment where participants had to steer a path with the stylus through a curved corridor on the surface of a graphic tablet/display, and we measured steering time, dispersion of trajectories, and applied force. Despite the variety of subjective impressions elicited by the different feedback conditions, we found that only nonvisual feedback induced significant variations in trajectories and an increase in movement time. In a post-experiment, using a pa…
Path Following in Non-Visual Conditions.
Path-following tasks have been investigated mostly under visual conditions, that is when subjects are able to see both the path and the tool, or limb, used for navigation. Moreover, only basic path shapes are usually adopted. In the present experiment, participants must rely exclusively on continuous, non-speech, and ecological auditory and vibrotactile cues to follow a path on a flat surface. Two different, asymmetric path shapes were tested. Participants navigated by moving their index finger over a surface sensing position and force. Results show that the different non-visual feedback modes did not affect the task's accuracy, yet they affected its speed, with vibrotactile feedback causin…
Might as well jump: Sound affects muscle activation in skateboarding
The aim of the study is to reveal the role of sound in action anticipation and performance, and to test whether the level of precision in action planning and execution is related to the level of sensorimotor skills and experience that listeners possess about a specific action. Individuals ranging from 18 to 75 years of age - some of them without any skills in skateboarding and others experts in this sport - were compared in their ability to anticipate and simulate a skateboarding jump by listening to the sound it produces. Only skaters were able to modulate the forces underfoot and to apply muscle synergies that closely resembled the ones that a skater would use if actually jumping on a ska…