UCT CS Research Document Archive

Topology Alteration for Virtual Sculpting using Spatial Deformation

Steyn, Barry and James Gain (2003) Topology Alteration for Virtual Sculpting using Spatial Deformation. In Proceedings AFRIGRAPH 2003: 2nd International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa, pages 63-68, Cape Town, South Africa.

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Virtual Sculpting enables the creation of computer models by emulating traditional sculpting. It can be implemented using spatial deformation, an interactive versatile modelling technique. Unfortunately, spatial deformation is limited to topology preserving warping. This is overcome by space-time objects, a variant of spatial deformation, which alters topology by extruding an object into 4-D, deforming the 4-D object and extracting a topologically altered object. However, they are specifically targeted to animation. In this paper, we adapt space-time objects to interactive modelling by: employing a tetrahedral rather than parallelepiped representation; exploiting coherence during the constant projection into four dimensions; and limiting projection to the portions of an object undergoing topology changes and thereby producing simpler triangulations of undeformed regions. Each of these adaptations is discussed in the context of the space-time object stages: extrusion, deformation and extraction. We also present preliminary results demonstrating the efficiency of our improvements.

EPrint Type:Conference Paper
Keywords:deformation, topology alteration
Subjects:I Computing Methodologies: I.3 COMPUTER GRAPHICS
ID Code:97
Deposited By:Gain, James
Deposited On:10 November 2003