## Collaborative Geometrical Modeling in Immersive Virtual Environments (1996)

Venue: | Proceedings Eurographics Workshop on Virtual Environments |

Citations: | 5 - 0 self |

### BibTeX

@INPROCEEDINGS{Usoh96collaborativegeometrical,

author = {Martin Usoh and Mel Slater and Tzwetomir I. Vassilev},

title = {Collaborative Geometrical Modeling in Immersive Virtual Environments},

booktitle = {Proceedings Eurographics Workshop on Virtual Environments},

year = {1996}

}

### OpenURL

### Abstract

. Although single person virtual environment systems can aid the individual in particular aspects of work they do not address issues of interaction and collaboration between participants and how these can enhance productivity. We present a system for geometrical modeling which permits collaboration between designers at physically separated sites to build and modify objects composed of free-form surfaces. The system is immersive therefore allowing workers not only to be in the same environment as the objects they're designing, but to come together and interact in the same extended space. In this context higher levels of interaction between workers must be used to cooperatively design and modify complex objects. We realise the importance of appropriate behaviour and provide tools which are intuitive in their use. These tools enable the designer to use natural hand and body motion to sweep out complex surfaces and to interactively deform and reshape them. These objects can in turn be seam...

### Citations

191 | Direct manipulation of free-form deformations
- Hsu, Hughes, et al.
- 1992
(Show Context)
Citation Context ...ractical for the designer to use direct manipulation of the control points to achieve a desired shape since the effect on the surface of manipulating a group of control points must be well understood =-=[6]. In line -=-with our theory of body centred interaction, direct manipulation of the surface became a goal. However, in order to provide an added sense of "reality" to the deformation process we opted fo... |

189 | Efficient, fair interpolation using Catmull–Clark surfaces
- Halstead, Kass, et al.
- 1993
(Show Context)
Citation Context ... 2 2 2 2 ] , (1) where the suffixes mean partial derivatives in respect to the parameters u and v. The integral (1) has the following advantages over the other functionals described in the literature =-=[8, 9, 10, 11]-=-: (a) Its minimisation leads to a linear system KuVKv = CuFCv T where V is the matrix of spline control points matrix, Ku and Kv are stiffness matrices, Cu and Cv are coefficients and F is the force m... |

97 | H.Qin, Dynamic NURBS with Geometric Constraints for Interactive Sculpting
- Terzopoulos
- 1994
(Show Context)
Citation Context ... 2 2 2 2 ] , (1) where the suffixes mean partial derivatives in respect to the parameters u and v. The integral (1) has the following advantages over the other functionals described in the literature =-=[8, 9, 10, 11]-=-: (a) Its minimisation leads to a linear system KuVKv = CuFCv T where V is the matrix of spline control points matrix, Ku and Kv are stiffness matrices, Cu and Cv are coefficients and F is the force m... |

78 |
Deformable curve and surface finite elements for free-form shape design
- Celniker, Gossard
- 1991
(Show Context)
Citation Context ... 2 2 2 2 ] , (1) where the suffixes mean partial derivatives in respect to the parameters u and v. The integral (1) has the following advantages over the other functionals described in the literature =-=[8, 9, 10, 11]-=-: (a) Its minimisation leads to a linear system KuVKv = CuFCv T where V is the matrix of spline control points matrix, Ku and Kv are stiffness matrices, Cu and Cv are coefficients and F is the force m... |

46 | Body Centred Interaction in Immersive Virtual Environments
- Slater, Usoh
- 1994
(Show Context)
Citation Context ...and modifying free-form geometric surfaces in immersive virtual environments. This was based B-Spline surfaces, and exploited an interaction model that we refer to as "body centred interaction&qu=-=ot; (BCI) [3]-=-. This interaction model is designed in an attempt to maximise the sense of presence of individuals in immersive environments. In this new work we have extended the sophistication of the underlying ge... |

34 |
Linear constraints for deformable B–spline surfaces
- Celniker, Welch
- 1992
(Show Context)
Citation Context |

18 |
A survey of cscw systems’, Interacting with
- Rodden
- 1991
(Show Context)
Citation Context ...stem deal with such a structure and how can communication be facilitated between the different groups. Since the mid 1980s such issues have been debated in Computer Supported Co-operative Work (CSCW) =-=[4]-=-. Investigations have been conducted using video and audio links where users can interact with a viewpoint from their own space. Now in the mid 1990s issues are being considered relating to participan... |

14 |
Distributed extensible virtual reality laboratory (DEVRL
- Slater, Usoh, et al.
(Show Context)
Citation Context ..., m.slater@cs.ucl.ac.uk 2 Permanent address for correspondence: ceco@ait.tu-rousse.bg participant applications. The philosophy of the project as a whole, and its various applications are described in =-=[1]-=-. In [2] we described an initial system for creating and modifying free-form geometric surfaces in immersive virtual environments. This was based B-Spline surfaces, and exploited an interaction model ... |

12 |
Taking Steps: The Influence of a Walking Metaphor on
- Slater, Usoh, et al.
- 1995
(Show Context)
Citation Context ...ace curve to a new target curve in the space. 3. Interactive Surface Creation One of the important aspects of our model for the enhancement of presence in immersive virtual environments (for example, =-=[12]-=-) is that there should be a strong correlation between sensory data (e.g., the visual input) and proprioception (correspondingly, the proprioceptive information generated by head movements). This matc... |

6 |
The Influence of Dynamic Shadows on Presence
- Slater, Usoh, et al.
- 1995
(Show Context)
Citation Context ...m model of dVS with the spline module at the visualisation level. At this level it is also possible to include other modules requiring fast dynamic modifications of polygons to aid model creation. In =-=[13]-=-, for example, we have noted the importance of dynamic shadows on presence and spatial awareness. Depth cues obtained from shadows cast by the virtual body or tool onto the sculpted surface or, one su... |

3 |
Modeling in Immersive Virtual Environments: A Case for the Science of VR
- Slater, Usoh
- 1995
(Show Context)
Citation Context ...er@cs.ucl.ac.uk 2 Permanent address for correspondence: ceco@ait.tu-rousse.bg participant applications. The philosophy of the project as a whole, and its various applications are described in [1]. In =-=[2]-=- we described an initial system for creating and modifying free-form geometric surfaces in immersive virtual environments. This was based B-Spline surfaces, and exploited an interaction model that we ... |

2 |
The mathematical basis of the UNISURF
- BEZIER
- 1986
(Show Context)
Citation Context ...most effectively investigated using systems which are able to deliver immersive capabilities. In describing the UNISURF CAD system, Pierre Bezier distinguished three classes of surface design problem =-=[5]-=-: . Objects that require great accuracy, that are of major technical importance for the product being designed, such as turbine foils or boat hulls; . Objects that are used only as part of an assembly... |

1 |
A Method for Fair B-spline Interpolation and Approximation by Insertion of Additional Data Points
- Vassilev
- 1996
(Show Context)
Citation Context ... below. Let w(u,v) = [x(u,v), y(u,v), z(u,v)] be a B-Spline surface parameterized by u and v, and let f(u,v) denote the applied sculpting forces on it. The energy functional for surfaces was employed =-=[7]-=- shown in Eq. (1). E = [c c c c c 1 2 2 2 3 2 4 2 5 2 w w w w w u v uu uv vv surface + + + + + + + - c c c dudv 6 2 7 2 8 2 2 w w w fw u v uv u v 2 2 2 2 ] , (1) where the suffixes mean partial deriva... |