Perforated Surface in Percentage

I'm a student Italian

congratulations for the forum, it's my first post!

I designed a panel with the holes using "voronoi" (img.1e2), obtaining the percentage perforated.
My question is: can I set the percentage of drilling before?
For example: I would like the panel is perforated to 53%.

Replies to This Discussion

Permalink Reply by David Rutten on September 18, 2013 at 9:33am

Got a bit sidetracked while looking into this, came across an interesting approach using blurring rather than scaling. I'll upload another file with target area logic in a bit.

David Rutten

david@mcneel.com

Tirol, Austria

Attachments:

SmoothingVoronoi.gh, 12 KB

Permalink Reply by David Rutten on September 18, 2013 at 12:51pm

Incidentally, if you vary the Blur Strength rather than the Iterations, then the algorithm becomes continuous and can be used to target a specific area. The change in area is not linear or indeed predictable, but Galapagos can deal with it:

In this case, Galapagos has been told to optimize the area to a value of 500

David Rutten

david@mcneel.com

Tirol, Austria

Attachments:

SmoothingVoronoi.gh, 11 KB

Permalink Reply by Antonella Scatamacchia on September 18, 2013 at 9:50am

thanks for the quick reply.
I have version 0.9.0014 and your file is not compatible.
perhaps I have not explained well: I have to drill a rectangle to 50% with 3 holes.
excuse my English.
thanks again

Permalink Reply by David Rutten on September 18, 2013 at 9:54am

You'll need to update if you want to open my files then.

David Rutten

david@mcneel.com

Tirol, Austria

Permalink Reply by David Rutten on September 18, 2013 at 9:52am

The logic is fairly simple, although the grasshopper network is a bit dense;

You know how much area you want to end up with. Let's call this A_Target.
You know how much area you have without any holes. Let's call this A_Base.
You can measure how much area your original voronoi curves have. Let's call this A_Curves.
You need to compute a scaling factor that will modify your curves, so that the total area goes from A_Curves to A_Target. Let's call this scaling factor f.
When you scale something with a factor f, the area changes as f². Thus, the scaling factor you're looking for is:
√ ((A_Base - A_Target) / A_Curves)