creating a folding pattern

hello everybody!

I'm fairly new to grasshopper and in order to get a basic understanding of the tool i am working my way through Zubin Khabazi's book "Generative Algorithms".

My goal for now is to write a definition that represents the following surface that I have created out of paper.

This is essentially a squared surface subdivided into triangular segments. For that reason I was hoping I could use Zubin's example about triangles in chapter 3 of his book.

I'm sure, you guys know these kind of folding technique, but to clarify the pattern of the surface, here's a quick diagram:

My approach was to use the point cloud out of Zubani's example and select points with the Cull Nth component according to the pattern shown in the diagram. These points I would then offset with a z-vector component while keeping the distance between the points fixed.

However, after spending now several days trying to figure this out, I definitely ran into a wall..

As I see it, the example generates multiple points for the same coordinates, meaning there are occasions where there 6 points on top of each other.

Further, the Cull Nth component doesn't work exactly as I've hoped, the problem lies in the transition from one row to another..

I was also thinking instead of creating a series of points and then trying to filter specific points out to create (a) the surfaces and (b) the offset, maybe I should start creating these separate lists from the beginning?

Or, instead of point cloud series, using a surface and the sDivide component?

As you see, I am pretty confused/lost in the problem... any help would be greatly appreciated!

Thanks!

Replies to This Discussion

Permalink Reply by gotjosh on August 7, 2011 at 3:35pm

i just shut down gh for the night, but maybe this idea helps: i would try to make one long zigzag to start (using series and points and a polyline).

then offset or move/duplicate it (consistently in the x, and alternating in the z)

not sure if mesh or surface is the better way to connect the zig zags...

i'll play with it tomorrow a bit if you don't solve it before i wake up...

cheers

Permalink Reply by Toby on August 8, 2011 at 1:06am

thanks for replying..

i managed to generate the zig zag lines:

however, I've realized that I've forgotten to mention that the zigzag lines need to be connected with diagonals as well:

Permalink Reply by gotjosh on August 8, 2011 at 12:13am

this will give a zig zag, with the z offset. does it match your model?

Permalink Reply by Toby on August 8, 2011 at 2:11pm

thanks..!

I managed to get the zig zag polylines, had to input a boolean series to the repeat component, though.

I've created a definition using a similar approach (just was easier for me to understand at this point)..

I was even able to get the diagonal connection lines in there..

however, when I try copying them over using series and a x-vector it sort of distributes them across the canvas.. not sure what exactly is happening there.. when I use just a number with the vector, everything works out fine..

this is the definition: