Géry Casiez

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We theoretically and empirically examine the impact of control display (CD) gain on mouse pointing performance. Two techniques for modifying CD gain are considered: constant gain (CG) where CD gain is uniformly adjusted by a constant multiplier, and pointer acceleration (PA) where CD gain is adjusted using a nonuniform function depending on movement(More)
Transfer functions are the only pointing facilitation technique actually used in modern graphical interfaces involving the indirect control of an on-screen cursor. But despite their general use, very little is known about them. We present EchoMouse, a device we created to characterize the transfer functions of any system, and libpointing, a toolkit that we(More)
Position control devices enable precise selection, but significant clutching degrades performance. Clutching can be reduced with high control-display gain or pointer acceleration, but there are human and device limits. Elastic rate control eliminates clutching completely, but can make precise selection difficult. We show that hybrid position-rate control(More)
Multi-touch displays represent a promising technology for the display and manipulation of 3D data. To fully exploit their capabilities, appropriate interaction techniques must be designed. In this paper, we explore the design of free 3D positioning techniques for multi-touch displays to exploit the additional degrees of freedom provided by this technology.(More)
Multi-touch displays represent a promising technology for the display and manipulation of data. While the manipulation of 2D data has been widely explored, 3D manipulation with multi-touch displays remains largely uncovered. Based on an analysis of the integration and separation of degrees of freedom, we propose a taxonomy for 3D manipulation techniques(More)
The 1e filter (“one Euro filter”) is a simple algorithm to filter noisy signals for high precision and responsiveness. It uses a first order low-pass filter with an adaptive cutoff frequency: at low speeds, a low cutoff stabilizes the signal by reducing jitter, but as speed increases, the cutoff is increased to reduce lag. The algorithm is easy to(More)
Isometric and elastic devices are most compatible with a rate control mapping. However, the effect of elastic stiffness has not been thoroughly investigated nor its interaction with control gain. In a controlled experiment, these factors are investigated along with user feedback regarding ease-of-use and fatigue. The results reveal a U-shaped profile of(More)
In this paper, we investigate the use of friction based tactile displays for the simulation of finely textured surfaces, as such displays offer a promising way for the development of devices with co-located vision and tactile feedback. The resolution of the textures rendered with such devices and their matching to real textures have never been investigated.(More)
This paper describes the use of user's focus point to improve some visual effects in virtual environments (VE). First, we describe how to retrieve user's focus point in the 3D VE using an eye-tracking system. Then, we propose the adaptation of two rendering techniques which aim at improving users' sensations during first-person navigation in VE using(More)
This paper studies the use of visual blur effects, i.e., blurring of parts of the image fed back to the user, for First-Person-Navigations in Virtual Environments (VE). First, we introduce a model of dynamic visual blur for VE which is based on two types of blur effect: (1) a Depth-of-Field blur (DoF blur) which simulates the blurring of objects located in(More)