Transform > Modify > Proportional Mod

Moves, rotates, or scales CVs relative to their proximity to a center “master” CV.

Proportional Mod Control

Operations: Choose whether to move, rotate, smooth, or non-proportionally scale the CVs.

Smooth – Interpolates the amount of change based on the Falloff values for averaging the CVs in the region of effect.

When Smooth is on, you select only the primary CV and the region of effect.
Move Mode: Choose XYZ to move CVs in world space.

Choose NUV to move CVs relative to their curve or surface.

NURBS Surface Options

Falloff

Specifies the degree of effect in the U and V parametric directions. The range for these fields is from -5.00 to 5.00.

The current Falloff value and the distance of each CV from its neighbor determines the amount by which the CVs before and after the selected ones are affected in relation to the primary CV. A Falloff value of 0 applies the transformation equally over the affected region.

If the Falloff value is positive, the effect of the transformation is decreased for CVs that are further away from the primary CV: the greater the value, the greater this damping effect. The greater the number of CVs between the primary CV and the boundary of the defined region, the less effect the transformation has on each CV. The higher the number, the less effect movement has on the surrounding CVs.
If the Falloff value is negative, the effect of the transformation is increased for CVs that are further away from the primary CV. The greater the number of CVs between the primary CV and the boundary of the defined region, the greater the effect of the transformation on each CV. Surrounding CVs move farther, because the effect is multiplied, but in the opposite direction.

Preceding #

Specifies the number of CVs before the primary CV that you want to include in the region definition along the U and V parametric directions.

The CVs that are affected by the operation range from 0 (the default) to N, where N is the maximum possible number of CVs in that direction for the object. Hence, to select all CVs in a direction, simply drag the slider all the way to the right.

Succeeding #

Specifies the number of CVs after the primary CV that you want to include in the region definition along the U and V parametric directions.

NoteFor a curve, only the U direction is used.

Revert button

Undoes all your modifications since you selected the currently active CVs.