Halftone pattern?

Hi everyone.

I want to create a halftone pattern like in the image below.

As inputs I imagine using a grid of points and assigning a value to each point to control the amount of black/white.

What I ultimately want to do is to control the pattern (on a facade) and decide which areas are white (transparent) and which are black (opaque). The final output will be a vector-drawing of the pattern.

Does anyone know how to go about this? I guess the tricky part is the gray-zone were the pattern shifts from black to white dots.

Thanks!

/Mårten

Replies to This Discussion

Permalink Reply by Daniel Piker on June 15, 2010 at 2:46pm

You could use the intersection of a pair of 2D scalar fields where one is some sine surface, and the height of the other is how black/white you want it to be.

The same thing works one dimension up too ;)

Attachments:

scalarintersect.ghx, 159 KB

Permalink Reply by kleerkoat on June 15, 2010 at 3:42pm

that's sick! (in a good way)

Permalink Reply by taz on June 15, 2010 at 4:13pm

Hey Dan,

Me thinks your number of sampling points in the u direction for the interpolated surfaces wants to be 31 (not 101). Otherwise the file throws some errors.

Looks like you were having too much fun and dialed it back a bit...

Cool beans though!

Permalink Reply by Mårten Nettelbladt on June 15, 2010 at 3:48pm

Awesome! Thanks a lot Dan.
I also tried creating the second surface by lofting some curves instead and it works really well too! (BTW, really funky preview there! Is that custom shaders in GH or a mix with baked geometry?)
Always great to get a reply from you! Many thanks.

Permalink Reply by Daniel Piker on June 15, 2010 at 5:15pm

Thanks guys.
Marten - yeah, it's baked geometry
Taz - I did indeed have the U points set to 101 initially, but then I replaced it with an addition component (original grid size + 1). Strange that it sounds like somehow when you are opening the file it is retaining its old values. I wonder if this is some sort of bug or version issue.

Permalink Reply by taz on June 16, 2010 at 10:28am

Yeah, I ignored the IO warnings, but now looking at the errors 0.6.0059 kicked [Addition] out (for some reason).

The first error is the one to watch for I suppose. Lesson learned.

Permalink Reply by Bennett Bossert on October 21, 2012 at 10:32pm

Hey guys,

I see this is an old discussion but I'm quite interested in the definition shown here. Does anyone have an updated version of this halftone pattern definition?

Thanks a lot!

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