Here is a displacement by attractors definition for grasshopper based on some real physics:
It allows you to set multiple ‘attractors’ which interact realistically just like electric charges, magnets, heat flows or ideal fluids. Sliders control whether each point is a source, sink, vortex or a combination of these.
Get the ghx here
edit 26/10/09 : Check out the new and improved 3D version – JellyFish
I’ve long been fascinated by this area of math/physics. For more on this, take a look at rheotomic surfaces (its a bit of a long read, but skip down to see all the pictures and videos)

March 10, 2009 at 10:58 pm
That’s bright guys…
Thanks for sharing!
March 24, 2009 at 12:03 am
[...] | Andrew Hudson has been making some beautiful curved-fold origami using grids from my recent work with magnetic [...]
April 5, 2009 at 10:11 am
[...] magnetic field sketch in Grasshopper controlling the metamorphosis of the MARS double corrugation pattern. Folded in [...]
April 6, 2009 at 5:08 pm
Cant seem to get the point grid to generate?
April 6, 2009 at 5:37 pm
nevermind, it was a preview issue
April 24, 2009 at 1:07 am
hey there i can’t get the *ghx…can anyone send it to me?
April 24, 2009 at 7:27 am
Sorry, the fileserver is down right now. I’ll fix this later today
Dan
April 27, 2009 at 7:19 am
The link should be working again now. Sorry about that
April 27, 2009 at 11:11 pm
still not working :((
April 28, 2009 at 12:01 pm
got it
thaaaaank you
May 1, 2009 at 4:54 am
is there something with the new grasshopper?
it says it opens grasshopper definitions as wrm’s (as opposed to ghx’s)
can you save your definition with the new file name?
thanks
May 1, 2009 at 6:31 am
i believe the file is corrupt, or has an error, there are continuous error messages that do not allow me to use the ghx.
i fixed the previous issue, but this one remains.
May 1, 2009 at 8:33 am
Benjamin – have you set the input points?
You need to make 4 pts in Rhino then reference them into grasshopper.
I’m pretty sure the problem is not with my file.
May 8, 2009 at 9:17 pm
HI Dan!
Looks great stuff….
wanna have a look to definition
but I am experiencing difficulties
when I open it in grasshopper
a list of errors show up….
Any suggestion?
Thank you
May 12, 2009 at 9:55 pm
Hi!
I experienced the same problem as Lorenz, with errors etc.
It looks interesting,
we would like to see it :)
May 12, 2009 at 10:14 pm
“errors etc” ???
could you be a bit more specific?
May 17, 2009 at 4:39 pm
Hi again!
I don’t know what kind of ‘error’ this is when I open the file..
When I open the ghx file a window pops up which says:
“IO generated 58 messages, would you like to see them?”
(yes or no)
and then when I click yes, there is a window with a label: “grasshopper archive messages”,
so there is no way to open the file
May 17, 2009 at 7:04 pm
Have you referenced in some points from rhino?
First make 4 points in rhino
Then link each of the 4 points on the left hand side of the GH definition to the rhino geometry.(right-click, ’set one point’)
The icon in GH should then change from orange to black and the definition will work.
let me know if you still have trouble
May 19, 2009 at 3:09 pm
Daniel,
Your electric field work is fantastic. I’m trying to understand the math and algorithms behind the solution for a project I’m working on. I also need to have evenly spaced lines, so I was hoping you could supply some advice. I’ve been looking at calculus & physics books for about a week. Did you calculate the lines using differential equations or did you use a geometric solution to convert a gradient field to a surface, then take sections?
June 4, 2009 at 10:51 am
I am having the same problem as everyone else. Nothing loads when I open the definition, so I have no option to input 4 points from Rhino. I only have the dialog box which says “IO generated 58 messages, would you like to see them?”. It would be really nice to be able to see this file. Can you list what version of Grasshopper you are saving in and what release of Rhino you are using. Please advise, Thanks.
June 5, 2009 at 10:47 am
This definition depends on you having an up-to-date version of grasshopper, get
version 0.60012 here, which I think solves these problems
June 5, 2009 at 10:51 am
Thanks for the tip. Installing the latest version of the WIP helped. Everything opened fine and I am working with it now. I appreciate you sharing this, it helps while I am learning Grasshopper.
June 8, 2009 at 9:11 pm
Hi Daniel,
We’re very interested in the organizations implied by the flowlines in the image at the top of this page, but in my experimentation with your magnetic displacement grasshopper definition, I haven’t been able to replicate this kind of effect. My question is, is it possible in grasshopper to create the system of isolines needed to achieve this, and if so can you give me any suggestions as where to begin?
June 8, 2009 at 9:53 pm
Hi Benjamin, Peter and others
Several people have been asking about the technique I used to generate the streamlines.
I can confirm that it is done in Grasshopper, and the definition is substantially different to the one posted here, and I haven’t yet shared it publicly.
I do intend to publish something on it, but have kept being busy with other things.
It is something I am quite attached to, and I think it is a unique and original method, so I want to make sure I do it justice. Many thanks for all your patience.
Dan
July 25, 2009 at 4:54 pm
Hey Daniel,
canĀ“t get it work…
defined the Pts in Rhino Viewport- but no Grid (as seen in the video) Preview is enabled – any suggestions?
Thanks Flo
July 25, 2009 at 5:38 pm
ok i made it- cplane issue
October 14, 2009 at 7:27 pm
what is a ghx file? do you have the definitions for the graphical interface?
October 14, 2009 at 9:34 pm
ghx is the format for grasshopper – a ‘graphical algorithm editor’ which works within the Rhino3D modeling program.
So sorry, this can’t be used without those programs. I think it would be reasonably easy to port to something like processing though.
October 20, 2009 at 6:59 am
Hi,
What is the best way to create the lines between the points of the grid?
Thanks
October 22, 2009 at 3:16 pm
[...] various ways of modeling with attractive and repulsive forces. It is a generalisation of my popular Magnetic Displacement definition to 3-dimensions, along with some other [...]