13.15. Circuit

13.15. Circuit
	13. Rendering Filters

13.15.1. Overview

Figure 16.315. Example of Circuit

Filter “Circuit” applied.

Circuit command is a script that fills the selected region (or alpha) with traces like those on the back of an old circuit board. It looks even better when gradmapped with a suitable gradient.

If the image is in indexed colors, this menu entry is grayed out and unavailable.

	Note
This filter creates a grey level image in RGB mode. The resulting image doesn't depend on the original image.

Note

This filter creates a grey level image in RGB mode.

The resulting image doesn't depend on the original image.

This effect is achieved through the following steps:

First, draw maze with 5 pixels width pathways and walls with the “Depth First” algorithm. The pattern of maze is set by Circuit seed.
Oilify this maze with a brush of Oilify mask size.
Then apply the extract edge filter with Sobel algorithm, Smear option and Amount to 2.0, to the oilified maze image. This crowds high contrast winding curves like as a circuit map.
Finally, Desaturate the map with gray color in RGB mode.

	Tip
	The effect seems to work best on odd shaped selections because of some limitations in the maze codes selection handling ability.

13.15.2. Activate the filter

This filter is found in the image window menu under Filters → Render → Circuit....

13.15.3. Options

Figure 16.316. “Circuit” filter options

Oilify mask size: With this option you can set the option value of the Oilify filter in pixels (range 3 to 50). Larger values make lines more fuzzy. 17 is the default value.
Circuit seed: You can give a randomizing seed number between 1 and 3000000. The default value is 3.
No background (only for separate layer): If this option is enabled, dark pixels of the circuit are made transparent so that the underlying image is shown through these holes. This option is disabled in default settings. The Separate layer option is required.
Keep selection: If an active selection exists when this script is called, you can keep the selection and its marching ants with this option. This option is enabled in default settings.
Separate layer: If this option is not checked, the generated texture is drawn on the active layer. When this option is enabled (in default), this script adds a layer to draw the circuit texture is on.