Click two points on a View window to define a circle. The radius of the circle defines how far the deformation is effective. Distance to the center of the circle is calculated for each point to get a deformation parameter. The control curve is then evaluated by the deformation parameter to get the amount of deformation. Click two points on a View window to define the scaling center and scale. Move the mouse to deform and click to accept the tool.
The Scale3D tool has the following options: