Trim Surface with Space Curve Property Editor

Projects a curve object onto a NURBS surface, either trimming the surface or creating a surface curve for use with other modeling operations.

To apply: Select a NURBS surface, choose Modify Surface Trim by Projection from the Model toolbar, and then pick a curve object.

To redisplay: Select the surface, click the Selection button on the Select panel, then click the Trim Surface with Space Curve icon.

Is Boundary	Determines which portion of the surface to keep when trimming rather than projecting: make a hole by keeping the area outside the curve (off), or crop the outside leaving only the interior (on).
Projection Precision	Controls the precision used for calculating the projection. If the shape of the projected curve is not accurate, increase the precision. However, high values take longer to calculate and may slow down your computer.
Choose Trims	Click to trim the surface using only some of the projected curves, and then pick the desired surface curves in a 3D view. Right-click when you have finished picking.
Trim With All	Click to trim the surface using all the projected curves. This is useful if you used Pick Trims or Project All and then changed your mind.
Project All	Click to simply project the curve onto the surface without trimming. The surface curves become components of the surface, and can be used in modeling operations like loft and others.