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, this effect is only available in Unity Pro and you must have the Pro Standard Assets installed before it becomes available.

Twirl image effect applied to the scene
RadiusThe 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).
AngleThe angle of rotation at the centre point.
CenterThe point at the centre of the circle where distortion occurs.

Hardware support

This effect requires a graphics card with pixel shaders (2.0) or OpenGL ES 2.0. PC: NVIDIA cards since 2003 (GeForce FX), AMD cards since 2004 (Radeon 9500), Intel cards since 2005 (GMA 900); Mobile: OpenGL ES 2.0; Consoles: Xbox 360, PS3.

All image effects automatically disable themselves when they can not run on end-users graphics card.

Page last updated: 2013-02-01