Version: 5.4 beta (switch to 5.3)
Tonemapping
Vignetting and Chromatic Aberration

Twirl

The Twirl image effect distorts the rendered image within a circular region. The pixels at the centre of the circle are rotated by a specified angle; the rotation for other pixels in the circle decreases with distance from the centre, diminishing to zero at the circle’s edge.

Twirl is similar to another image effect called Vortex, although vortex distorts the image around a central circle rather than a single point.

As with the other image effects, you must have the Standard Assets Effects package installed before it becomes available.

Twirl image effect applied to the scene
Twirl image effect applied to the scene

Properties

Property: Function:
Radius The radius of the ellipse where image distortion occurs, given in normalized screen coordinates (ie, a radius of 0.5 is half the size of the screen).
Angle The angle of rotation at the centre point.
Center The point at the centre of the circle where distortion occurs.

Hardware Support

This effect should run on all hardware that Unity supports.

Tonemapping
Vignetting and Chromatic Aberration