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Cords: Geometric Curve Primitives for Modeling Contact
May/June 2006 (vol. 26 no. 3)
pp. 72-79
Patrick Coleman, University of Toronto
Karan Singh, University of Toronto
The modeling of curves that contact complex 3D geometry presents a challenge to animators and designers. Parametric curve models specified with control points often require an intractable amount of position constraints to achieve a desired shape, in particular if the curve is animated and has changing contact relationships. Physical simulations model contact, but they are difficult to control with precision, especially for complex scenes. This article presents a geometric curve primitive, known as a cord, which allows for interactive modeling of curves that contact complex geometry. A cord is constructed from a user-positioned guide curve, which specifies an approximate path the cord should follow with respect to geometry. This guide curve, along with a small set of appearance properties, parameterizes a geometric construction that is capable of capturing the visual appearance of a variety of materials, including strings, wires, and rubber bands.

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Index Terms:
curve modeling, contact modeling, surface contact
Patrick Coleman, Karan Singh, "Cords: Geometric Curve Primitives for Modeling Contact," IEEE Computer Graphics and Applications, vol. 26, no. 3, pp. 72-79, May-June 2006, doi:10.1109/MCG.2006.54
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