ECAD–A Prototype Screen-based VR Solid Modeling Environment Incorporating Tangible Deformable Models

Two shortcomings of the current generation of computer-aided design (CAD) software are (1) segregating the tasks of modeling and simulation, and (2) casting inherently 3D tasks, such as modeling and manipulation, into a 2D environment. The former is due to the fact that modeling is generally an interactive process whereas simulation often must be conducted off-line due to the computational cost of traditional simulation methods. The latter arises largely from the relative newness of 3D interface devices and the lack of software that takes good advantage of them. In this paper we present a screen-based VR modeling and simulation environment called ECAD (Enhanced CAD). ECAD is a proof-of-concept system that combines 6 DOF input, 3D visualization, haptic feedback, and a new real-time deformation simulation engine into a unified modeling and simulation environment. Real-time simulation of deformations provides the user with immediate tangible feedback regarding the behavior of the model, allowing for more rapid design iteration and encouraging the trial-and-error exploratory shape modification typical in the early conceptual phase of design. 3D interfaces to the modeling environment also improve the overall flow of information between the user and the computer model. Stereoscopic display, haptic feedback, and 6 DOF interface devices allow for a much more intuitive interaction with the model and improved task completion times. We describe the modeling environment and show demonstrative examples.