Minimal distance between points?

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Permalink Reply by JW on August 24, 2012 at 12:48pm

Here is what I've done so far

Attachments:

• grass.jpg, 345 KB

Permalink Reply by Andrew Kudless on August 24, 2012 at 3:19pm

You could do this in a couple of ways. The easy way would be to use the populate 2D component as it has a built-in function that distributes the points so that they are farther away from each other while still being random. Then translate the XYZ points into UV points and use Evaluate Surface to place these points on a reparameterized surface. 

The more difficult way would be to use Kangaroo to create a spring network on the surface. With the right settings this could push the points away from each other into some sort of optimized position where any two points are as far away from each other as possible while still bing on the surface and not too close to any other point.

Permalink Reply by JW on August 24, 2012 at 5:58pm

Thank you Andrew! What is the best way to then get these points to move in the direction they are perpendicular to of say between 0 and 1mm positively or negatively randomly (or say Y direction). I think I am there with it I just don't want the surface to look too smooth, I want it be more faceted looking if that makes sense. Sorry this is my first day at using this program. Thank you for your help!

Permalink Reply by Andrew Kudless on August 25, 2012 at 5:07pm

I'm not exactly sure what you mean, but I think you are asking to be able to add a bit more noise into the point distribution. That is, the populate 2D made things too uniform for you?

If that is the case then you can take the points from the populate 2D component and either decompose the points into their XYZ values and add a random number between -1 and +1 to each X and Y value.

Or, if you want to get a bit more advanced and start using vectors, you could create a random X vector with a length of -1 to +1 and a one for Y too (using a different random seed) and then add them together. Then move each of the original points by that vector.

Also, that random reduce in your file is not needed. Just use the Number of Points slider (which should be an integer slider) to control the points rather than taking some away after they have been created. 

Permalink Reply by Ali Naghavi on August 24, 2012 at 3:00pm

Excuse me JW for interruption but I faced another question:why when I put the seed for the engines same numbers the points place on a line It is wierd for me and I cant realize it !!!

it is actually more about the random component and it is not relevant to your question!

tnx

Permalink Reply by Andrew Kudless on August 24, 2012 at 3:15pm

The random component in Grasshopper is actually more of a pseudo-random component. The seed determines the series of random numbers that it will produce. This is useful as it would be annoying if every time you opened a definition with the random component it used a different set of random values. The seed allows us to have consistency with our randomness. If you change the seed values so that they are different for your X and Y values they will no longer line up.