"Effect: Vortex" dialog box

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.