Curve and COS Offset tool updates
A New Offset Measure option in the Curve and COS Offset tool lets you choose between using Chordal Length and Arc Length for the Offset Distance.
When set to Chordal Length, offset distance is based on the shortest linear distance between the input and the offset output. When set to Arc Length, this distance is based on the arc length of the input surface. Use Arc Length when you want the offset length measured on the surface length. Otherwise, choose Chordal Length for a linear offset distance.
The two new options are only available when the input is a surface edge, curve on surface, surface span or isoparm. These options are not available when offsetting a curve.
For more information, see the following: