The Glow image effect (sometimes called "Bloom") can dramatically enhance the rendered image by making overbright parts "glow" (e.g. sun, light sources, strong highlights). The Bloom image effect gives greater control over the glow but has a bit higher processing overhead.

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.

Glow effect applied to the scene


Glow IntensityTotal brightness at the brightest spots of the glowing areas.
Blur IterationsNumber of times the glow is blurred when being drawn. Each iteration requires processing time.
Blur SpreadThe pixel distance over which pixels are combined to produce blurring.
Glow TintColor tint applied to the glow.
Downsample ShaderThe shader used for the glow. You generally should not have to change this.


Glow uses the alpha channel of the final image to represent "color brightness". All colors are treated as RGB, multiplied by the alpha channel. You can view the contents of the alpha channel in Scene View.

All built-in shaders write the following information to alpha:

Most of the time you'll want to do this to get reasonable glow:


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