Harmony Draw Guide > Effects > Using Effects > Blur-Directional Directional-Blur


The Directional-Blur effect creates the effect of a motion blur that pulls and smears the image from one contour edge to a different direction or angle. This effect is useful in creating the impression of speed, such as the streaks of colour that follow a car travelling at high speed.

Use the Directional-Blur editor to control the settings of the Directional-Blur effect.

Directional-Blur Property Editor

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.

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.
Falloff Rate 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.

The direction of the blur. Enter a value from 0 to 360.

0: Blurs the image to the west.

90: Blurs the image to the south.

180: Blurs the image to the east.

270: Blurs the image to the north.

Direction of trail If you do not set an Angle for the direction of the blur, you can select a direction (north, south, east, or west) from this menu. The calculations for this feature are faster than the calculations for the Angle setting.
Ignore Alpha Controls the leading edge of the blur. Deselect this option for a solid or hard leading edge on the blur.
Extra Final Blur Adds a second blur after the Directional-Blur is created. If you have a Directional-Blur that begins at 0 and gradually gets stronger, deselect this option to ensure a smooth progression.
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.