Random point grid

Hi,

Classic newbie question: I want to generate a point grid with a random z-direction position for each point. Grasshopper generates a series of random numbers per point rather than a single one. I tried random reduce and culling but stil end up with a single same values for all points. ANy suggestions? I am using the x,y,z point function and feeding a series of values into it for the x and y positions.

Replies to This Discussion

Permalink Reply by Marios Tsiliakos on March 8, 2012 at 4:54pm

Is this what you want to achieve?? try to change the seed number in each random number generator..

Regards M.

Permalink Reply by cadebe on March 9, 2012 at 7:24am

Hi Marios,

It's getting better in that at least the rows are individually randomised. The issue lies with the grid length function. The list length function retrieves 6 as the value of the list length (assume 6 x6 grid), hence the rows of 6 identical random values. It seems to me that the list should be 6x6 but this does not work in the right way. I would still like to have each of the values in the entire grid at a single individual random value. How do I get around this? I tried longest list, cross referencing etc.

Attachments:

ghx image.jpg, 118 KB

Permalink Reply by Hannes Löschke on March 9, 2012 at 7:34am

two concepts you need to understand:

1) Random returns a repeatable "random" sequence of numbers. The Sequence changes with different "Seed" values.

2) List/Tree logic in GH. There's a list of points for each row in the grid. Each row needs to get its own list of random values. Right now you create only one list, that gets applied to each row.

Input a list of [number of rows] seeds into the Random component. Graft this input so every Seed greates its own list of values.

Permalink Reply by Vicente Soler on March 9, 2012 at 7:53am

You just need to flatten the P output.

Also, I recommend you enable "draw fancy wires" under the view menu.

Permalink Reply by Marios Tsiliakos on March 9, 2012 at 8:26am

I second that (enabling fancy wires). You can either flatten the point-list from the beginning as Vicente suggests, or following my screenshot by flattening the z output and then "re-grafting" it. you can flatten/graft either by component or by right-clicking on the input symbol.

Permalink Reply by cadebe on March 10, 2012 at 1:23pm

Superb. Thank you for all the generous advice.

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