G2 continuity

Hi rhino community, i have a question for you.
Why are there 2 numbers when verifying curvature continuity of 2 surfaces? what do they correspond to?
Thank you !

Hi Enzo - from Help:


Evaluates curvature deviation between the selected edge pair.

This option displays absolute and relative (in parentheses) deviations.

  • Absolute curvature deviation = (1/Radius1)-(1/Radius2)
  • Relative curvature deviation = (Radius1-Radius2)/(Radius1+Radius2)


Thank you Pascal !
And what number should i aim to have nice continuous reflexions ? Absolute : 0 and relative :1 ?

If Radius 1 equals Radius 2 then the relative curvature difference = 0 and absolute curvature difference = 0.

However if Radius1 is infinite (Curvature1 = 0, ie “flat”) and Radius2 is infinite (Curvature2 = 0, ie “flat” then relative curvature difference is undefined. However Rhino returns a value of 1 even though the curvatures match.

What is needed to be satisfactory for the intended application. Exact matching will look good, but in many instances less than exact will be satisfactory.

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