As a suggestion for Rhino3dm in .NET, it would be a nice convenience if the Rhino.Geometry.Line.ToNurbsCurve() function set the domain from 0.0 to the line length, rather than from 0.0 to 1.0. This is due to my observation that the domain interval of NurbsCurve appears to be set equal to a curve’s length in Rhino3D. Indeed, when using the Rhino.Geometry.NurbsCurve.EpsilonEquals() function to compare two NurbsCurves, the same tolerance is applied to the differences in knot intervals as the difference in control points. This implies that the knots and control points have the same units, i.e. the model units. Normalising the domain when converting a Line to a NurbsCurve means this no longer holds. It is easy enough to adjust the domain of a Line converted to a NurbsCurve, which automatically updates the knots, but it would be a nice convenience if this was how the Rhino.Geometry.Line.ToNurbsCurve() function operated so that no subsequent domain adjustment was necessary.