JVRC09: Joint Virtual Reality Conference of EGVE - ICAT - EuroVR
https://diglib.eg.org:443/handle/10.2312/368
ISBN 978-3-905674-20-02024-03-19T05:45:59Z3-Hand Manipulation of Virtual Objects
https://diglib.eg.org:443/handle/10.2312/EGVE.JVRC09.153-156
3-Hand Manipulation of Virtual Objects
Aguerreche, Laurent; Duval, Thierry; Lécuyer, Anatole
Michitaka Hirose and Dieter Schmalstieg and Chadwick A. Wingrave and Kunihiro Nishimura
In this paper we introduce a new 3D interaction technique called '3-Hand Manipulation', for multi-user collaborative manipulation of 3D objects. The 3-Hand Manipulation relies on the use of three manipulation points that can be used simultaneously by three different 'hands' of two or three users. Interestingly, the three translation motions of the manipulation points can fully determine the resulting 6 degrees of freedom motion of the manipulated object. We describe the implementation of the 3-Hand Manipulation, its graphical representations and an illustration of its use by two or three users on an insertion task in immersive virtual environment. This technique could be used in various applications of collaborative VR such as for virtual prototyping, training simulations, assembly and maintenance simulations.
2009-01-01T00:00:00ZModification of Visual and Vestibular Control of Posture by Long-term Adaptation to Body-movement-yoked Visual Motion and Galvanic Vestibular Stimulation
https://diglib.eg.org:443/handle/10.2312/EGVE.JVRC09.137-143
Modification of Visual and Vestibular Control of Posture by Long-term Adaptation to Body-movement-yoked Visual Motion and Galvanic Vestibular Stimulation
Kitazaki, Michiteru; Kimura, Takuya; Inoue, Yasuyuki; Matsuzaki, Naoyuki
Michitaka Hirose and Dieter Schmalstieg and Chadwick A. Wingrave and Kunihiro Nishimura
Human postural control is a multi-modal process with visual and vestibular information. Thus, postural sway is induced by visual motion as well as vestibular stimulation. The purpose of this study was to measure individual differences in weights on vision and vestibular senses to control posture, and to investigate if the individual weights could be modulated by long-term adaptation to visual motion or galvanic vestibular stimulation (GVS). GVS was applied through left and right mastoid processes (0.1-0.5mA, sinusoidal amplitude modulation). Both visual motion and GVS induced lateral (leftward-rightward) postural sway back and forth. Observers' body movement was measure by a force plate and a magnetic motion tracker. We measured observers' postural sway induced by visual motion or GVS before and after a 7-days adaptation task (n
2009-01-01T00:00:00ZInfluence of Orientation Offset between Control and Display Space on User Performance during the Rotation of 3D Objects
https://diglib.eg.org:443/handle/10.2312/EGVE.JVRC09.129-136
Influence of Orientation Offset between Control and Display Space on User Performance during the Rotation of 3D Objects
Dang, Nguyen-Thong; Pergandi, Jean-Marie; Crison, Franck; Ardouin, Jérôme; Mestre, Daniel
Michitaka Hirose and Dieter Schmalstieg and Chadwick A. Wingrave and Kunihiro Nishimura
This paper presents an exploratory investigation of the influence of orientation offset between control and display space on user performance in three-dimensional rotation tasks. A target-matching task was chosen as an experi-mental task; participants had to rotate an object (using an input device with 3 degree-of-freedom (DOF) in rota-tion) so that it matched the target, which was an object identical to the controlled object. Orientation of the con-trolled object was offset relative to the target's orientation by 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330 degrees. Those offsets were separately applied to each of the 3 axes of the target (vertical (X), horizontal (Y) and depth (Z) axes). Completion time and time series of orientation of the input device were collected. Results show strong effects of high values of offset (from 90° to 150° and from 210° to 270°) on user performance and user be-haviour. In addition, there was a difference in user performance and behaviour between orientation offsets on the Z-axis and those on the two other axes, apparently due to the form of the input device that was used. The findings from this investigation may contribute to the design of 3D input devices (with regard to issues on physical form-factors and on supports for rotation in particular) and that of techniques for the manipulation of 3D objects.
2009-01-01T00:00:00ZReorientation during Body Turns
https://diglib.eg.org:443/handle/10.2312/EGVE.JVRC09.145-152
Reorientation during Body Turns
Bruder, Gerd; Steinicke, Frank; Hinrichs, Klaus; Lappe, Markus
Michitaka Hirose and Dieter Schmalstieg and Chadwick A. Wingrave and Kunihiro Nishimura
Immersive virtual environment (IVE) systems allow users to control their virtual viewpoint by moving their tracked head and by walking through the real world, but usually the virtual space which can be explored by walking is restricted to the size of the tracked space of the laboratory. However, as the user approaches an edge of the tracked walking area, reorientation techniques can be applied to imperceptibly turn the user by manipulating the mapping between real-world body turns and virtual camera rotations. With such reorientation techniques, users can walk through large-scale IVEs while physically remaining in a reasonably small workspace. In psychophysical experiments we have quantified how much users can unknowingly be reoriented during body turns. We tested 18 subjects in two different experiments. First, in a just-noticeable difference test subjects had to perform two successive body turns between which they had to discriminate. In the second experiment subjects performed body turns that were mapped to different virtual camera rotations. Subjects had to estimate whether the visually perceived rotation was slower or faster than the physical rotation. Our results show that the detection thresholds for reorientation as well as the point of subjective equality between real movement and visual stimuli depend on the virtual rotation angle.
2009-01-01T00:00:00Z