Blur - Box

The Blur - Box effect is a quick and easy way to create a blurring effect. The Box blur changes the colour value of each pixel based on the pixels next to it in the vertical and horizontal directions. The look of the blur is similar to the look achieved using Gaussian blur, but renders much faster. This effect is useful when a faster rendering time is important, and the quality of the blur is less important. Also, you can use a matte with this effect to isolate areas of the image.

For detailed video tutorials and sample scenes by Adam Phillips, see


Blur - Box Effect Properties

Parameter Description
Truck Factor Activated by default, this option readjusts the blur when the elements undergo a change of depth or scale. When this option is deselected, the effect's values remain unchanged regardless of any depth or scale changes. This option should be deselected when multiple drawings are composited and attached to this effect.
Repeat Edge Pixels Makes the blur algorithm operate as if the pixel values beyond the edge of the layer are the same as the values of the edge pixels. This keeps edges sharp, preventing them from darkening and becoming more transparent.
Blurriness Amount of blur applied to the layer.

Blurs according to the length, width, and angle you specify. For example, if a character is walking east, the blur may fall to the west.

Length: Length of the blur.

Width: Thickness of the blur.

Angle: The direction in which the blur is applied: sideways, up, down, 90 degrees, 45 degrees, and so on.

Radius Size of the blur. The larger the value, the greater the strength or reach of the blur. The blur radius is affected by the drawing scale and camera position. Click the Edit Curve button to change these values over time by adjusting the function curve.
Bidirectional Applies the blur on both sides of the pixel.
Fall Off The distance where the blur fades from the edge of the image. Select a value between 0 and 1. A fall-off rate of 0 causes the blur to fade out slowly, distributing the blur evenly from the edge of the character to the farthest edge of the blur. A fall-off rate of 1 causes the blur to fade out quickly, so the blur is heaviest closer to the edge of the image.
Number of Iterations The number of times the blur is applied to the image. A higher number of iterations creates smoother transitions between colours and increases the blur, but also increases render time.