# Spesific hole pattern on surface

Hello all,

I’m super new to Rhino and grasshopper and I’m strugeling a bit with my project. I want to build an object that has a spesific pattern on it and it is perforated by it ( pictures attached). I tried out to do it with Voronoi but since it is an spesific pattern, Voronoi just makes it all random. I also tride the Image sampeling but it only works with shapes and not with an even surface (?) So I would really apreciate your advise since I just couldn’t find anything that is getting me any further.
The Black dots are the pattern, the sketch is the idea of the final look of my object.

Best Wishes
Mau

Hi Mau - is there any reason this needs to be done in GH and not simply drawn directly in Rhino using the image as a background to trace against?

Something like that?

-Pascal

1 Like

Thank you for the fast replay!
Part of the assigment is to use GH and get to know some of the tools it has. So the whole concept of this is to make something like a flower pot with the plant inside the object and growing through the gaps. So I want to repeat the pattern multiple times on the whole surface. The object has to stay hollow for it to fork as planed.

something like this. Dose this make sense ?

-Mau

If you must use Grasshopper, then you’ll need the following steps:

1. Convert bitmap with holes to curve outlines.
2. Orient curves perpendicular to the hole direction.
3. Convert curves to planar surfaces and extrude them far enough to extend beyond the surface you’re cutting.
4. Cut the holes using Boolean Difference.

The first step is the hard one as there is no component which converts a bitmap into outline curves. However you can:

1. Import the bitmap into an Image Sampler
2. Randomly sample its brightness at many locations using points from the Populate2D component. (Just make sure your populate component uses the same bounds as the image.)
3. Adjust the point z values according to the brightness. So white points are at elevation 1.0 while black points remain at elevation 0.0
4. Fit a mesh through the points with Delaunay.
5. Intersect this mesh with a horizontal plane with elevation 0.5
6. Possibly do some smoothing on the resulting polylines.
7. Finally fit a nurbs curve though those polylines so you end up with smooth, rather than segmented, hole oulines.

You can use Rooster

hole.gh (86.0 KB)

3 Likes

Thank you very much!
I’m trying it that way, I might just use curves for the Patterns and then extrude and boolean them on the object !