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Smooth command

Averages the positions of curve and surface control points and mesh vertices in a specified region.

The Smooth command evens out the spacing of selected control points in small increments. This command is useful for removing unwanted detail, and for removing loops in curves and surfaces.

On mesh objects use the Weld command  before smoothing in order to prevent the mesh from pulling apart.


number_onestep.gifSelect curves, meshes, or surfaces to smooth and press Enter.

The selected entities will appear to melt, losing detail due to the averaging of the positions of the control points.

To smooth part of a curve or surface

number-1.pngSelect a curve or surface to smooth.

number-2.pngUse the PointsOn command to turn on the object's control points.

number-3.pngSelect the control points in the region of the curve or surface to smooth.

number-4.pngStart the Smooth command.

number-5.pngClick the checkboxes for the coordinate directions and adjust the Smooth factor.

Note: To set one check and clear the others, right-click the checkbox.

The selected control points will move slightly, smoothing the curve or surface.

Smooth Options

Smooth X/Smooth Y/Smooth Z

Smooths only in the specified x-, y-, or z-direction.

Fix Boundaries

Prevents edges and endpoints from being included.

Meshes: Vertices along naked edges will not be modified.

Curves: End control points will not be modified.

Surfaces: The control points along the boundaries of the surface will not be modified. The edges and trims of trimmed surfaces will be modified if they do not coincide with the surface boundary.


round_bullet.gifIf all of the object control points are selected, Rhino perceives this as the whole object being selected.

round_bullet.gifFix Boundaries may cause undesirable seams or singularities in closed curves and surfaces.

World coordinates/CPlane coordinates

Use world or construction plane coordinates to determine the direction.

Smooth factor

0 to 1

The curve control point toward the average.

Greater than 1

The curve control point moves past the average.


The curve control point moves away from the average (roughing).

See Also

Edit surfaces.