Terrence Fernando, Norman Murray, Kevin Tan, Prasad Wimalaratne
The Centre for Virtual Environments
University of Salford
UK.

Virtual environment technology is now beginning to be recognised as a powerful design tool in industrial sectors such as Manufacturing, Process Engineering, Construction, Automotive and Aerospace industries, offering the ability to visualise a design from different viewpoints by engineers from different design perspectives providing a powerful design analysis tool for  supporting concurrent engineering philosophy. A common weakness of the current commercial virtual environments is the lack of efficient geometric constraint management facilities such as run-time constraint detection and the maintenance of constraint consistencies for supporting accurate part  positioning and constrained 3D manipulations. The environments also need to be designed to support the user as they are completing their task. This paper describes the software architecture of a constraint-based virtual environment that supports interactive assembly of assembly parts, embedded within a task based environment that supports contextual help and allows for the structure of tasks to be altered easily for rapid prototyping.