Random points in a volume,.?

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Permalink Reply by Daniel Piker on September 26, 2009 at 11:18am

Easiest way would be to make the Bounding box of the volume and put random points in that, then use the 'inside' component to test pts for inclusion in the volume, and cull those that aren't

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Permalink Reply by David Rutten on September 26, 2009 at 11:24am

Hi Krish,

a while ago there was a discussion regarding distirbuting random points inside a custom volume while making sure that no two points are closer than x units. I cannot find it now, but I ended up writing a VB component to solve this.

If you do not care about point-proximity, then it becomes a much easier problem. Simply generate a box of random points (using 3 random components to control the x, y and z coordinates of a list of points) and then remove all the points that fail the inside/outside.

Just be sure to pick different seed values for all your random generators, otherwise you'll end up with the same random sequence three times.


--
David Rutten
david@mcneel.com
Seattle, WA

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Permalink Reply by voronoiii on October 1, 2009 at 1:38pm

Thanks daniel and david,..
I tried as you suggested,.. i am stuck at the end,.. about how to remove the points which are not inside the volume,.
Can u check the GH & rhino and let me know how to remove them,..
And also i have a general doubt about the random points,.. No matter wat ever seeds im giving for X,Y,Z,.. im able to find some pattern in those points in some or the other views, i mean they are not completly random, do you know why,.? may be i should post some images to be more clear about wat im saying,..?
Thank you

Attachments:

• random point in a fluid volume.ghx, 136 KB
• Random points in a volume.3dm, 48 KB

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Permalink Reply by voronoiii on October 1, 2009 at 2:13pm

I have one more Question,..
I am trying to get a pattern/series of numbers,.. Can u see the image and let me know how can i achieve that series of numbers,.??

Attachments:

• Pattern image.jpg, 90 KB

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Permalink Reply by Vicente Soler on October 1, 2009 at 3:31pm

Use the 'mass addition' component under scalar -> util.
The 'Pr' output will return what you are looking for.

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Permalink Reply by voronoiii on October 1, 2009 at 4:19pm

got it,.. thanks a lot,...

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Permalink Reply by voronoiii on October 1, 2009 at 4:56pm

Hey vicente,
Do u know how to remove a list of points that come under 'false' after using "inside/outside" component?
I was trying to find random points in a volume, so i used bounding box and then inside/outside component, but after this how to remove all the 'false' points that are outside the volume,.?
thanks

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Permalink Reply by unfinal on May 20, 2012 at 3:38pm

I am really need to know how to make sure that no two points are closer than X units in GH..haha..

and i google a lot and here is the only answer.. 

I wanna distirbuting random points. and I wanna know how to make sure that no tow points closer than X..

Thanks a lot..if you have a solution:)

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Permalink Reply by klumpen on May 22, 2012 at 7:47pm

Im too trying to find a solution to that problem. Please let me know if/when you have found a way. thanks

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Permalink Reply by klumpen on May 23, 2012 at 3:28pm

ok, i got it. just use the newer "populate 2D" component. this component makes sure the point population is smooth (no too cose points). this is quite important to know - it should be mentioned in the "right-click-help".

but i havent figured out what good the "Optional pre-existing population" input is good for?

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