Generalized God-Objects: a Paradigm for Interacting with Physically-Based Virtual World

In this paper, we show a method to interact with physically-based environments in a way which guarantee their integrity whatever the mechanical properties of the virtual interaction tool and the control device. It consists in an extension of the god-object concept. The interaction tools are modeled as physical bodies which tend to reach, if possible, the position maintained by the user. Their behavior is computed via the dynamic laws of motion by the simulation engine, as the other bodies in the scene. The cases of articulated rigid bodies and deformable bodies are studied. This mechanism also provides a unified framework which allows the control of virtual objects via devices providing force feedback or not. Finally, some applications including virtual surgery are shown to illustrate the effectiveness of the approach.

[1]  Blake Hannaford,et al.  A two-port framework for the design of unconditionally stable haptic interfaces , 1998, Proceedings. 1998 IEEE/RSJ International Conference on Intelligent Robots and Systems. Innovations in Theory, Practice and Applications (Cat. No.98CH36190).

[2]  Christophe Chaillou,et al.  A Physically-Based Virtual Environment Dedicated to Surgical Simulation , 2003, IS4TH.

[3]  Aerospatiale Matra Ccr,et al.  Simulating Haptic Information with Haptic Illusions in Virtual Environments , 2000 .

[4]  Marie-Paule Cani,et al.  Combining physically-based simulation of colliding objects with trajectory control , 1995, Comput. Animat. Virtual Worlds.

[5]  David L. Zeltzer,et al.  A New Model for Efficient Dynamic Simulation , 1993 .

[6]  J. Baumgarte.  Stabilization of constraints and integrals of motion in dynamical systems , 1972 .

[7]  Elizabeth A. Croft,et al.  Haptic feedback using local models of interaction , 2003, 11th Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, 2003. HAPTICS 2003. Proceedings..

[8]  John Kenneth Salisbury,et al.  A constraint-based god-object method for haptic display , 1995, Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots.

[9]  James J. Troy,et al.  Six degree-of-freedom haptic rendering using voxel sampling , 1999, SIGGRAPH.

[10]  Christophe Chaillou,et al.  A deformable body model for surgical simulation , 2000, Comput. Animat. Virtual Worlds.

[11]  Christophe Chaillou,et al.  A fast implicit integration method for solving dynamic equations of movement , 2001, VRST '01.

[12]  Julien Lenoir,et al.  Mixing deformable and rigid-body mechanics simulation , 2004, Proceedings Computer Graphics International, 2004..

[13]  John F. Canny,et al.  Haptic interaction with global deformations , 2000, Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065).

[14]  David Baraff,et al.  Linear-time dynamics using Lagrange multipliers , 1996, SIGGRAPH.

[15]  Oussama Khatib,et al.  The haptic display of complex graphical environments , 1997, SIGGRAPH.

[16]  J. Edward Colgate,et al.  Issues in the haptic display of tool use , 1995, Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots.

[17]  Christian Laugier,et al.  Realistic haptic rendering for highly deformable virtual objects , 2001, Proceedings IEEE Virtual Reality 2001.

[18]  Oussama Khatib,et al.  DYNAMIC MODELS FOR HAPTIC RENDERING SYSTEMS , 1998 .

[19]  Jane Wilhelms,et al.  Collision Detection and Response for Computer Animation , 1988, SIGGRAPH.