With the 3D Scale gizmo, you can resize selected objects and subobjects along an
axis or plane, or resize the objects uniformly.

The 3D Scale Gizmo shortcut menu offers options for aligning, moving, or changing
to another gizmo.

The following prompts are displayed.

Select objects

Specifies the objects to be scaled.

Specify base point

Specifies the base point for the scaling.

Pick a scale axis or plane

Specifies whether the object is scaled uniformly or only along a specific axis or
plane. You have the following choices:

• Scale uniformly. Click the area closest to the vertex of the 3D Scale gizmo. The interior region of
  all axes of the gizmo is highlighted.
  
• Constrain the scale to a plane. Click between the parallel lines between the axes that define the plane. This option
  is only available for meshes, not solids or surfaces.
  
• Constrain the scale to an axis. Click the axis. This option is only available for meshes, not solids or surfaces.
  

Specify scale factor

Specifies the amount of change. Drag to dynamically modify the size of the selected
objects or enter a scale value. For example, enter 2 to double the size of the selection.

Copy

Creates and scales a copy of the selected objects.

Reference

Sets a scale based on a ratio.

• Reference length. Sets the relative amount that represents the current size in the scale ratio.
• New Length. Sets the relative value used to calculate the new size. For example, if the reference
  length is 1 and the new length is 3, the size of the selected objects is tripled.
• Points. Specifies the relative value used to calculate the new size based on two points that
  you specify.