Curve Edit > Curve Planarize

Modifies a curve or surface edge so all its points lie on the same plane.

Often used to prepare curves for use as profile curves, or for the Set Planar tool.

Curve Planarize Options

Default Projection Plane

Best – Calculate the plane that best fits the existing curve (the plane that forces the least modification to the curve).

Axis – Flatten the curve onto an axis plane (XY, YZ, or XZ).

User Defined Plane – Flatten the curve onto an existing construction plane.

View – Calculate the plane from the view vector (perpendicular to the active window) and the vector joining the end CVs of the row.

The following option appears when the Default Projection Plane is Best.

Lock Ends

Do not move the endpoints while flattening. Locking ends allows you to maintain existing intersections.

The following options appear when the Default Projection Plane is Axis.

Principal Plane

Choose a plane (XY, YZ, or XZ) to flatten the curve onto.

Keep Originals

Keep the old curve(s) after flattening.