# Generative Design Variations M.4.2.3 Attractor curves

A short description from the Generative Design book: ‘When calculating the force, the formula contains the fixed number 0.5, which is multiplied by a new parameter. In order to name this parameter appropriately, one needs to examine how this multiplication changes the curve. Obviously, the more quickly the curve reaches its highest point, the greater the value. The parameter could therefore be called ramp. The corresponding line in the attractor class could be as follows:

float f = 1 / pow (s, 0.5 * ramp) – 1;

When examined closely, a bend in the curve at the radius is visible, meaning that an unattractive kink would occur on the graph as well. This kink is eliminated when the following formula is used to calculate the force:

float s = pow (d / radius, 1 / ramp);

float f = s * 9 * strength * (1 / (s + 1) + ((s – 3) / 4)) / d;’

Here you can find the original program.
M_4_2_03

I could not put the programs online because the programs are not supported by JavaScript because JavaScript does not support the Generative Design Library. So I have prepared a Flickr Album which contains all still images I have made during this assignment. You can find those clicking this link:
GDV_M_4_2_3

The links below the paragraphs will redirect you to the Flickr page with the image I describe in that actual paragraph. I began with inverting the fills and background color. Changed the grid size to 800 x 800 pixels. XCount and yCount are on 801 (xCount and yCount is the amount of nodes). Left all settings as they were but made a few variations with them. Ah… the pdf-file turns out to be just a black document. Changed the grid-size back to 600. When I reset everything the pdf-file does contain an image but it doesn’t look like the one which is generated by Processing without creating a png file. Checked the file in Photoshop and it contains no image. So I do not worry about that and continue with working with png’s. Made same variations with these grey moiré patterns.
M_4_2_03_GDV_01

I decreased the attractor radius of impact (influence size on the nodes) to 50. The nodes themselves (xCount and yCount are 701 x 701. Which means you get a finer pattern in the display window. In fact it is just the same pattern as in the previous sketch.
M_4_2_03_GDV_02

I decreased the attractor radius of impact (influence size on the nodes) to 500. Did not change anything else. And than you get these moiré patterns. A bit more harsh and somewhat less refined.
M_4_2_03_GDV_03

Increased the radius of impact for the attractor to 800 pixels. XCount and yCount are on 201. I use rectangles made of 8 x 4 pixels. Made a few variants with different rectangle sizes. Interesting that these patterns are not depending on the shapes they are created with.
M_4_2_03_GDV_04

Decreased xCount and yCount. Gridsize is increased. The attractor strength is 4 times as high (in the negative) and the attractor ramp is doubled. Interesting to see that ellipses which enter the borders are piling up to each other. This gives a kind of rough photo-edge. But in the end I decided to clean it up because I found it disturbing for the final image.
M_4_2_03_GDV_05

This version is the inverted variation of the previous sketch.
M_4_2_03_GDV_06

Tried to make some variations with 3 ellipses of different size and position.
M_4_2_03_GDV_07

Five variations with five different cubes under different angles. Cube front left, front right front outside, front inside, front transparent.
M_4_2_03_GDV_08

Made five variations with lines only. They are not perfect but I think this imperfection is not a negative thing in this case.
M_4_2_03_GDV_09

Made four patterns with different objects. Two flower and leaflike patterns. One with honeycombs and used some ellipses for more flowers in this time of the season.
M_4_2_03_GDV_10