To Create a Curve from Sharp Facet Edges
1. Click
Restyle >
Curve >
From Sharp Edges.
2. Select points on the faceted data that lie on the sharp edge of the facet model. Middle-click to finish selection.
◦ Selection of a single point causes the creation of a curve that follows the sharp edge.
◦ Selection of multiple points causes the creation of an open curve that approximately passes through the selected points while following the sharp edge.
|  The resulting curve is a curve on facets. It can be used to create domains and for automatic surfacing. |