361 research outputs found
Digital sculpture : conceptually motivated sculptural models through the application of three-dimensional computer-aided design and additive fabrication technologies
Thesis (D. Tech.) - Central University of Technology, Free State, 200
Influence of Haptic Communication on a Shared Manual Task in a Collaborative Virtual Environment
International audienceWith the advent of new haptic feedback devices, researchers are giving serious consideration to the incorporation of haptic communication in collaborative virtual environments. For instance, haptic interactions based tools can be used for medical and related education whereby students can train in minimal invasive surgery using virtual reality before approaching human subjects. To design virtual environments that support haptic communication, a deeper understanding of humans' haptic interactions is required. In this paper, human's haptic collaboration is investigated. A collaborative virtual environment was designed to support performing a shared manual task. To evaluate this system, 60 medical students participated to an experimental study. Participants were asked to perform in dyads a needle insertion task after a training period. Results show that compared to conventional training methods, a visual-haptic training improves user's collaborative performance. In addition, we found that haptic interaction influences the partners' verbal communication when sharing haptic information. This indicates that the haptic communication training changes the nature of the users' mental representations. Finally, we found that haptic interactions increased the sense of copresence in the virtual environment: haptic communication facilitates users' collaboration in a shared manual task within a shared virtual environment. Design implications for including haptic communication in virtual environments are outlined
The feasibility of using virtual prototyping technologies for product evaluation
With the continuous development in computer and communications technology the use of
computer aided design in design processes is becoming more commonplace. A wide range of
virtual prototyping technologies are currently in development, some of which are commercially
viable for use within a product design process. These virtual prototyping technologies range
from graphics tablets to haptic devices. With the compression of design cycles the feasibility of
using these technologies for product evaluation is becoming an ever more important
consideration.
This thesis begins by presenting the findings of a comprehensive literature review defining
product design with a focus on product evaluation and a discussion of current virtual
prototyping technologies. From the literature review it was clear that user involvement in the
product evaluation process is critical. The literature review was followed by a series of
interconnected studies starting with an investigation into design consultancies' access and
use of prototyping technologies and their evaluation methods. Although design consultancies
are already using photo-realistic renderings, animations and sometimes 3600 view CAD
models for their virtual product evaluations, current virtual prototyping hardware and software
is often unsatisfactory for their needs. Some emergent technologies such as haptic interfaces
are currently not commonly used in industry. This study was followed by an investigation into
users' psychological acceptance and physiological discomfort when using a variety of virtual
prototyping tools for product evaluation compared with using physical prototypes, ranging from
on-screen photo-realistic renderings to 3D 3600 view models developed using a range of
design software. The third study then went on to explore the feasibility of using these virtual
prototyping tools and the effect on product preference when compared to using physical
prototypes. The forth study looked at the designer's requirements for current and future virtual
prototyping tools, design tools and evaluation methods.
In the final chapters of the thesis the relative strengths and weaknesses of these technologies
were re-evaluated and a definitive set of user requirements based on the documentary
evidence of the previous studies was produced. This was followed by the development of a
speculative series of scenarios for the next generation of virtual prototyping technologies
ranging from improvements to existing technologies through to blue sky concepts. These
scenarios were then evaluated by designers and consumers to produce documentary
evidence and recommendations for preferred and suitable combinations of virtual prototyping
technologies. Such hardware and software will require a user interface that is intuitive, simple,
easy to use and suitable for both the designers who create the virtual prototypes and the
consumers who evaluate them
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