Expert for Grasshopper / Rhino modelling needed!

Hey all,

Let me explain the structure and the problem:
I have several square geometry. The dimension of each square is 4,5cm x 4,5cm. The material is a thin pice of paper.

My goal is to transform (overlap) the cuts in the middle with several angles. So I wanna create different geometries with the same form. The overlapping angle swayed the highest geometrie point in the middle.

The next step is to connect these squares and create some arches. The hardest point is to create with different parameters in grasshopper different angles to show what is happening.

I hope u can help me! Thanks a lot!

Best regards

Replies to This Discussion

Permalink Reply by Konstantin Schuster on May 27, 2017 at 5:45am

More pictures ...

Permalink Reply by Joseph Oster on May 27, 2017 at 9:07am

Intersecting cones? The cones are easy, the intersections and trimming got a bit ridiculous and has unwanted fragments... Adjusting base surface, cone radius and height, can help but there must be a better way:

P.S. Creating the base surface got weird too, since lofting three arcs resulted in a brep (two surfaces instead of one!?). Hence, the silly 'Divide' curves and 'IntCrv' before 'Loft'. WTF?

Attachments:

cones_2017May27a.gh, 21 KB

Permalink Reply by Joseph Oster on May 27, 2017 at 1:41pm

Changed UV from 6 X 4 to 8 X 6, reduced cone radius from 9 to 6.5 and added a "de-frag" group (yellow) to filter small trimmed fragments by area (< 5). Could trim the ends with planes, as I did the bottom, but will leave something for you to do, Konstantin. ;)

Attachments:

cones_2017May27b.gh, 24 KB

Permalink Reply by Joseph Oster on May 27, 2017 at 2:24pm

Instead of making all the cones the same, make radius and height proportional to the area of each subsurface:

Attachments:

cones_2017May27c.gh, 26 KB

Permalink Reply by Konstantin Schuster on May 28, 2017 at 1:11pm

WOW! You are a real Pro! Thank you for this amazing and gorgeous grasshopper structure and pictures. I am very happy right now! They will help me a lot!

I have some further detail points and I dont know how to solve them. You will find them in the Attachments. Maby you can help me:

1. Attachment: Is it possible to cut / transform the arch at the beginning and end of the structure to a line and not with an arch?

2-5. Attachment: Is it possible to create seperate arches with six of the pattern? I want to create seperate arches to string them to each other. Do u know what I mean?

Gerneral questions:

- Is it also possible to work with a square and not with a cone? I don't think so. Right?

- Is it possible the make the three arches in your definition flexible (high, width, span ...)?

Thank you very much for your time and nice help! It's amazing!

Permalink Reply by Joseph Oster on May 28, 2017 at 3:12pm

Hah! Assigning homework? Not gonna happen, sorry. Hope you can learn more about Grasshopper by studying the code I posted but remember, this is not the only way.

I'll try to answer a couple of your questions.

1. Attachment: Is it possible to cut / transform the arch at the beginning and end of the structure to a line and not with an arch?

Yes, I already suggested that you can do that yourself, similar to the way I trimmed off the parts below the "ground plane". Give it a try.

2-5. Attachment: Is it possible to create seperate arches with six of the pattern? I want to create seperate arches to string them to each other. Do u know what I mean?

No, I don't really know what you mean? From the attachments, it appears that you want "separate overlapping arches", so to adapt the method I used (intersecting cones), each arch would be a separate surface, yes. Many ways to do that... Reminds me of this thread where 'SDivide' was used, alternate "rows" of points are moved outward using surface normal vectors, new 'IntCrvs' are created and lofted. Despite the thread title, the idea will work on any surface, not just egg shaped:

http://www.grasshopper3d.com/forum/topics/wrap-surface-around-egg

- Is it also possible to work with a square and not with a cone? I don't think so. Right?

Doesn't make sense to me but TRY IT! If you don't understand the code completely, though, you won't succeed at modifying it...

- Is it possible the make the three arches in your definition flexible (high, width, span ...)?

Of course! It doesn't really matter how you create the surface(s), as long as you understand the relationship between various dimensions. For example, I chose the cone radii to be as small as possible without leaving any holes between them - based purely on visual inspection. This is part of the "art" of GH.

Some of the methods I used will fail for different reasons when the parameters go "out of bounds". One of the more obscure details, along with 'Divide' and 'IntCrv', is that I reversed the order of the three curves so that surface normal vectors point out instead of in... understand?

One of the most important basic skills with Grasshopper is being able to find where it fails by using 'Preview' and/or looking at the text output of components using panels and/or other means.

OK, honestly, this code is likely beyond your skill level at this point so I probably shouldn't be doing this, but it's fun for me so... I'll implement the "overlapping arches" feature using the code I mentioned from January, with a few tweaks to make sure the arches don't intersect each other. Please show me that you understand it by making some significant changes of your own and posting them here?

Attachments:

cones_2017May28a.gh, 30 KB

Permalink Reply by Konstantin Schuster on June 5, 2017 at 5:36am

Hey, Joseph! Thanks for your response.

I tried to trim the cones in the front and back, but it doesnt work very well ;).

I worked with an plane in the z direction to trim the cones. With this definition I got a lot of trouble ;). I got the most problems in the end with the "equals" and "dispatch" buttons. Can u help me or solve the problem? I worked some hours on it :(.

In the 2nd gh-definition I tried to work with "flexible arches". It worked but there were in the intersection areas a lot of problems ...

Attachments:

Versuch die Cones seitlich abzuschneiden.gh, 28 KB
Flexible Bögen als Loft.gh, 25 KB

Permalink Reply by Joseph Oster on June 5, 2017 at 8:23am

In your first file (Versuch die Cones seitlich abzuschneiden.gh), you ignore the trimmed output from the white group above it. Why? Instead, start with the trimmed, clean output from the yellow "de-frag" group and split/trim it.

Permalink Reply by Joseph Oster on June 5, 2017 at 10:56am

I worked some hours on it :(.

Guess what? I've worked "some hours" on this too! Didn't mean to make it look or sound easy. So I'm not going to post or explain this code today. The screen shot is explicit enough, I think.