Abstract
Parametric splines curves are typically constructed so that the firstn parametric derivatives agree where the curve segments abut. This type of continuity condition has become known asC n orn th orderparametric continuity. It has previously been shown that the use of parametric continuity disallows many parametrizations which generate geometrically smooth curves.
We definen th ordergeometric continuity (Gn), develop constraint equations that are necessary and sufficient for geometric continuity of curves, and show that geometric continuity is a relaxed form of parametric continuity.G n continuity provides for the introduction ofn quantities known asshape parameters which can be made available to a designer in a computer aided design environment to modify the shape of curves without moving control vertices. Several applications of the theory are discussed, along with topics of future research.
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Barsky, B., DeRose, T.D. Deriving the beta-constraints for geometric continuity of parametric curves. Seminario Mat. e. Fis. di Milano 63, 49–87 (1993). https://doi.org/10.1007/BF02925094
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DOI: https://doi.org/10.1007/BF02925094