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Action:
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Evaluates a the principal curvatures and directions at the given uv on the surface
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Filename:
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kern/kern_scm/surf_scm.cxx
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Syntax:
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(surface:eval-curvatures srf su sv )
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Arg Types:
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srf
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surface
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su
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real
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sv
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real
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Returns:
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real ...
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Description:
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This extension finds the two principal curvatures of the surface at the given parameter values. It also returns the directions of the principal curvatures.
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srf specifies the surface to evaluate.
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su specifies the
u parameter value.
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sv specifies the
v parameter value.
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Limitations:
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This extension does not take account of surface discontinuities, so that evaluating the curvatures at such points may be unreliable, as no attempt is made to compute sided curvatures
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Example:
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;surface:eval-curvatures
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;; Create the surface
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(solid:wiggle 50 50 50 "anti")
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;; #[entity 1 1]
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;; (ray:queue 258.188 -312.023 293.684 -0.537024 0.628851 -0.562273 1)
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(define f (pick-face))
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;; f
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(surface:eval-curvatures (surface:from-face f) .5 .5)
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;; (0.067385584485619 #[gvector -0.576407926659592
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;; -0.281960099592504 -0.766976143254649]
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;; 0.120983661175455 #[gvector -0.595361733728196
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;; 0.787806079907338 0.157816306106784])
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