Diffusion Limited Aggregation - v1.0,  © 2010 Richard Rosenman Advertising & Design. Release date: 10/07/10, Updated --/--/--.


INSTALLATION:

Simply unzip "dla.zip" and copy "dla.8bf" to your "\Photoshop\Plug-Ins\" folder, or whichever plugin folder your host program uses. Load your program, open an image, go to the plugins menu and select the plugin.


DESCRIPTION:

This filter will generate diffusion limited aggregations. Diffusion-limited aggregation (DLA) is the process whereby particles undergoing a random walk due to Brownian motion cluster together to form aggregates of such particles. This filter is based on Paul Bourke's DLA algorithm: http://local.wasp.uwa.edu.au/~pbourke/.

Play: Computes the aggregation based on the number of iterations. The further the start location is from the attractor and the larger the image size is, the slower the computation. As the aggregation closes in to the attractor color, the computation times will steadily decrease.

Iterations: Defines the maximum number of cycles to compute. The default value of 100 is strictly for testing and you will want a much higher value for any significant aggregations.

Position X,Y: Defines the horizontal and vertical start location when not using image pixel emitters. The range of -100 to +100 maps across the left/up and right/down image extents.

Stickiness: Controls the thickness of the aggregation. A stickiness of 100% will result in thinner aggregations whereas lower values will result in thicker ones.

Aggregation Color: Defines the aggregation color. Any image pixels of the exact same color will also act as emitters. For instance, if your aggregation color is solid yellow RGB(255,255,0) and your image has pixels of identical color yellow RGB(255,255,0), these pixels will also act as emitters. (See "bg01.bmp")

Aggregation Color Img: Will use only image emitters for start location. If using image pixels of the exact same color for emitters, you may not want to also use the start location pointer. This feature will disable the start location pointer.

Attractor Color & Threshold: Defines the aggregation attraction color and threshold. In order for Diffusion Limited Aggregation to work, you MUST specify an attractor color and your image MUST have a pixel or more of this color visible in the preview window so that the aggregation has a target to move towards. This color swatch specifies the attractor color and the threshold specifies a limited tolerance value. For instance, if your attractor color is solid green RGB(0,255,0) but your image has shades of green RGB(4,253,2), the threshold will allow for this shade of green to be included as an attractor color. The higher the threshold, the more variance is accepted.

BG Color: Defines the background color when enabled. When using your own image for emission, attraction and repellence pixels, you may not want this to be included in your final render. This feature allows you to color the background a solid, specified color and still use the image's pixel information.

BG Color Pushbutton: Enables or disables the background color.

Repellent Color & Threshold: Defines the aggregation repellent color and threshold. Diffusion Limited Aggregation allows repellent colors which will block the aggregation and cause it to change direction. You can create unique paths and behaviors using this feature. This color swatch specifies the repellent color and the threshold specifies a limited tolerance value. For instance, if your repellent color is solid red RGB(255,0,0) but your image has shades of red RGB(253,2,4), the threshold will allow for this shade of red to be included as an repellent color. The higher the threshold, the more variance is accepted. (See "bg02.bmp")

Reset: Resets all values to default.

Realtime: Applies all effects (in realtime) on 'mouse drag' instead of on 'mouse release'.


KNOWN BUGS:

NONE.


FIXES:

NONE.


HOMEPAGE:

http://www.richardrosenman.com
