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Action:
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Evaluates the curvature vector of an edge at the specified SPAparameter.
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Filename:
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kern/kern_scm/crv_scm.cxx
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Syntax:
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(curve:eval-curvature edge parameter)
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Arg Types:
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edge-or-curve
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curve | edge
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parameter
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real
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Returns:
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gvector
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Errors:
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EDGE with no CURVE
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Description:
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The parameterization of all curves is normalized to lie in the interval 0 to 1, therefore, evaluating at parameter=0 indicates the start point of the curve.
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edge-or-curve specifies an edge or a curve
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.parameter specifies the length of the curve to evaluate. If the specified parameter lies outside the range 0 to 1, this extension returns an implicit position. A spline can only reliably be evaluated for parametric values from 0 to 1; if
parameter is outside of this range for a spline edge, the returned value is meaningless.
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Example:
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; curve:eval-tan
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; Create a circular edge.
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(define edge1 edge:circular
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(position 0 0 0) 38 0 100))
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;; edge1
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; Evaluate the curvature at a specific parameter.
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(curve:eval-curvature edge1 0.23)
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;; #[gvector -0.024223811932959 -0.0102823981181388 0]
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