A convertor and user interface to import CAD files into worldtoolkit virtual reality systems

Virtual Reality (VR) is a rapidly developing human-to-computer interface technology. VR can be considered as a three-dimensional computer-generated Virtual World (VW) which can sense particular aspects of a user's behavior, allow the user to manipulate the objects interactively, and render the VW at real-time accordingly. The user is totally immersed in the virtual world and feel the sense of transforming into that VW. NASA/MSFC Computer Application Virtual Environments (CAVE) has been developing the space-related VR applications since 1990. The VR systems in CAVE lab are based on VPL RB2 system which consists of a VPL RB2 control tower, an LX eyephone, an Isotrak polhemus sensor, two Fastrak polhemus sensors, a folk of Bird sensor, and two VPL DG2 DataGloves. A dynamics animator called Body Electric from VPL is used as the control system to interface with all the input/output devices and to provide the network communications as well as VR programming environment. The RB2 Swivel 3D is used as the modelling program to construct the VW's. A severe limitation of the VPL VR system is the use of RB2 Swivel 3D, which restricts the files to a maximum of 1020 objects and doesn't have the advanced graphics texture mapping. The other limitation is that the VPL VR system is a turn-key system which does not provide the flexibility for user to add new sensors and C language interface. Recently, NASA/MSFC CAVE lab provides VR systems built on Sense8 WorldToolKit (WTK) which is a C library for creating VR development environments. WTK provides device drivers for most of the sensors and eyephones available on the VR market. WTK accepts several CAD file formats, such as Sense8 Neutral File Format, AutoCAD DXF and 3D Studio file format, Wave Front OBJ file format, VideoScape GEO file format, Intergraph EMS stereolithographics and CATIA Stereolithographics STL file formats. WTK functions are object-oriented in their naming convention, are grouped into classes, and provide easy C language interface. Using a CAD or modelling program to build a VW for WTK VR applications, we typically construct the stationary universe with all the geometric objects except the dynamic objects, and create each dynamic object in an individual file

Human factors consideration in the interaction process with virtual environment

Newrequirements are needed by industry for computer aided design (CAD) data. Some techniques of CAD data management and the computer power unit capabilities enable an extraction of a virtual mock-up for an interactive use. CAD data may also be distributed and shared by different designers in various parts of the world (in the same company and with subcontractors). The use of digital mock-up is not limited to the mechanical design of the product but is dedicated to a maximum number of trades in industry. One of the main issues is to enable the evaluation of the product without any physical representation of the product but based on its virtual representation. In that objective, most of main actors in industry domain use virtual reality technologies. These technologies consist basically in enabling the designer to perceive the product in design process. This perception has to be rendered to guarantee that the evaluation process is done as in a real condition. The perception is the fruit of alchemy between the user and the VR technologies. Thus, in the experiment design, the whole system human-VR technology has to be considered

A Steel Bridge Design System Architecture using VR-CAD and Web Service-based Multi-Agents

This paper presents a new design environment based on Multi-Agents and Virtual Reality (VR). In this research, a design system with a virtual reality function was developed. The virtual world was realized by using GL4Java, liquid crystal shutter glasses, sensor systems, etc. And the Multi-Agent CAD system with product models, which had been developed before, was integrated with the VR design system. A prototype system was developed for highway steel plate girder bridges, and was applied to a design problem. The application verified the effectiveness of the developed system

Integrated Earthquake Simulator to Generate Advanced Earthquake Disaster Information

Realistic simulation of possible earthquakes is crucial for producing a rational counter plan against earthquake disasters. This paper presents such a simulation method, the Integrated Earthquake Simulator (IES), which uses a computer-based high-resolution strong ground motion (SGM) simulator and a Virtual Reality (VR) city constructed from GIS/CAD data. The IES is an integrated computer system that is intended to simulate all phases of earthquakes numerically: earthquake hazards, earthquake disasters, and human and social actions against earthquake disasters. An efficient combination of GIS/CAD data and numerical simulation tools for each phenomenon on this computer system can achieve integrated earthquake simulation. This paper presents the methodology of reconstruction of a VR city and the IES prototype. An example of a VR city model is reconstructed and some earthquake disaster simulations are undertaken to examine the IES performance

D3: an Immersive aided design deformation method

International audienceIn this paper, we introduce a new deformation method adapted to immersive design. The use of Virtual Reality (VR) in the design process implies a physical displacement of project actors and data between the virtual reality facilities and the design office. The decisions taken in the immersive environment are manually reflected on the Computed Aided Design (CAD) system. This increases the design time and breaks the continuity of data workflow. On this basis, there is a clear demand among the industry for tools adapted to immersive design. But few methods exist that encompass CAD problematic in VR. For this purpose, we propose a new method, called D3, for "Draw, Deform and Design", based on a 2 step manipulation paradigm, consisting with 1) area selection and 2) path drawing, and a final refining and fitting phase. Our method is discussed on the basis of a set of CAD deformation scenarios

Human factors consideration in the interaction process with virtual environment

International audienceNew requirements are needed by industry for computer aided design (CAD) data. Some techniques of CAD data management and the computer power unit capabilities enable an extraction of a virtual mock-up for an interactive use. CAD data may also be distributed and shared by different designers in various parts of the world (in the same company and with subcontractors). The use of digital mock-up is not limited to the mechanical design of the product but is dedicated to a maximum number of trades in industry. One of the main issues is to enable the evaluation of the product without any physical representation of the product but based on its virtual representation. In that objective, most of main actors in industry domain use virtual reality technologies. These technologies consist basically in enabling the designer to perceive the product in design process. This perception has to be rendered to guarantee that the evaluation process is done as in a real condition. The perception is the fruit of alchemy between the user and the VR technologies. Thus, in the experiment design, the whole system human-VR technology has to be considered

A general purpose cave-like system for visualization of animated and 4D cad modeling

In the last decade, virtual reality (VR) systems have been used to enhance the visualization of CAD projects. The immersive VR techniques allow to the designer interacting and modeling in a more intuitive and efficient way. Current 4D and animated simulation CAD tools are a new challenge for immersive visualization. In this paper we propose a general purpose cave-like system that enables interactive visualization of 4D and animated CAD models. In an automated way, the system is able to treat static and dynamic 3D environments, allowing to share the experience of navigation in the scene among the users, even geographically distributed. The collaborative immersive multiprojection visualization approach has basically four modules for modeling, converting, visualizing and interacting. Besides the system had be designed and implemented for visualization of CAD models, it can be used for general purposes thanks to the use of a XML-based format on the visualization module. The system proposed is validated through a case-study using dynamic 3D models created on digital manufacturing softwares of Shipbuilding and Offshore Industries