Used to apply a vortex-like effect.
[Center] field
The center of the effect is displayed. The position of the center is specified by dragging the mark, provided in the dialog preview display.
[Radius] field
The radius of the effect is displayed as a number of pixels. The radius is specified by dragging the mark, provided in the dialog preview display.
[Angle] slider
Used to specify the angle of vortex rotation within a range of 0 to 720.