This research aims at the realization of a networked virtual environment for the design of three-dimensional (3-D) objects. Based on an analysis of an ordinary collaborative design, we illustrate that a collaborative work space consists of a dialog space and an object space . In the dialog space, a participant interacts with partners, and in the object space with an object. The participants enter the dialog space and the object space in turn, appropriately. In addition, collaborative design of 3-D objects is carried out with multimodal interactions: visual, auditory, and haptic. A networked virtual environment must support these interactions without contradiction in either time or space. In this paper, we propose a networked virtual environment for a pair of participants to satisfy the conditions described above. To implement the networked system, we take into account the necessity of visual, auditory, and haptic interactions, the need for participants to switch between the dialog space and the object space quickly and appropriately, and human ergonomics on the functional space of hands and eyes. An experiment on hand-over task was done to investigate the effect of the networked haptic device with the proposed system. Object layout tasks, such as toy block layout, office furniture layout, city building layout, etc., can be performed by using this environment.

This paper describes a 3D kinesthetic interface device using tensed strings. The results of the experiments on pick-and-place tasks show that not only sensations of collision but also weights of virtual objects are important in virtual environments.