Need help about using Kangaroo for form finding

Dear all the experts in Kangaroo,

I newly learned to use Kangaroo to do form finding.

However, the tutorial is not clear and I met an error in my practice.

The .3dm and .gh documents are attached. Can anyone help me to solve this error?

Much thanks,

Xue Zhengyu

Attachments:

error document.gh, 19 KB
error.3dm, 73 KB

Replies to This Discussion

Permalink Reply by peter fotiadis on December 18, 2015 at 9:08am

I'm pretty sure that David would ban both of us (you for no(?) reason, me for a variety of reasons, he he).

Moral: Karma

May the Force (the Pink option) be with you

best, The Merciless

Attachments:

Rectangles_on_grid_V1.gh, 113 KB

Permalink Reply by Zhengyu Xue on December 18, 2015 at 9:21am

Dear Godlike Karma,

I really like your humor!!

It does not make sense for David to ban me, but will be a big fault to ban you. No worry!

Best,

Cuppuccino

Permalink Reply by peter fotiadis on December 18, 2015 at 9:53am

BTW: Some simple T joints (but for a double tetra tensegrity) are posted here (don't ask how the T trusses are(?) involved(?)).

http://www.grasshopper3d.com/forum/topics/equal-distance-between-po...

Permalink Reply by peter fotiadis on December 18, 2015 at 10:29am

BTW: Get this (minus the cables: life sucks). If you want the cables ... mail me an original hymn to Ducati (MUST be lyric and passionate AND Honda insulting). Classic Ducatis (the proper ones, I warn you; like a 888 SPS) must been explicitly nominated on that epic thingy.

BTW: The (a bit primitive) method used to create something (a module of a XTruss, that is) on the WordXY Plane and then transform it to the related planes ... well it's not a T on surface by the book (but I guess that nobody could notice it).

Additionally this XTruss can be rigid with regard the central node... a thing that greatly facilitates the whole case (and dramatically reduce the cost AND the FEA time on the members).

Moral: Ducati Uber Alles.

Attachments:

Life_sucks_V2A.gh, 132 KB

Permalink Reply by Zhengyu Xue on January 5, 2016 at 1:53am

Geachte Lord of Olympus,

Beste Wensen & Gelukkig Nieuwjaar!After the long long Christmas , everybody get back to work. I wish you had a wonderful holiday.

So far most of my ideas are stated in the proposal I sent you by email. Your replies are of great help. I have applied your "Rectangle" file in my GH model. At this moment, I've made a lot effort to build the model parametrically, what I need now is to apply different ways for form-finding to get some possible shapes.

Here I will consult another question: how to make vectors along the lines ? As is shown in the pic below, I want to apply external radiant pattern force pointing from all the top points to the lower center point. I tried to use the command "vector 2Pt" but found the resulting vectors starting from the base point (0,0,0) .

Best,

Mr. Hang Me with Pretensioned cables

Permalink Reply by peter fotiadis on January 5, 2016 at 3:03am

Dear King of NeverIsTooLateButMaybeItIs

This is included in some C# that I've provided to you (but I've lost count of them, blame Alzheimer).

Anyway:

For a given grid Point3d p and an apex Point3d:

Vector3d vDir = apex - p; Line line = new Line (p, p + vDir);

Point3d pAtLine = line.PointAt(somethingBetween0and1);

Permalink Reply by Zhengyu Xue on January 13, 2016 at 12:40am

Dear Lord of Darkness,

When I was making my GH model, I frequently met the problems to connect points with line segments and to consider various lists into one. I have solved them by using the components in GH. It seems simple to script them, but I always get some error. Can you help me with the following two questions?

How to connect a list of points with line segments? .____.____.____.____. (there are 5 points, draw the in between four lines with c#)
How to merge 3 lists of points into one list in the right order?

List 1 . list 2 . . . . list 3 . . (7 points in total to be merged in one list with the given order)

Best,

Mr. Pepper Fried Meat

Permalink Reply by peter fotiadis on January 13, 2016 at 2:42am

Dear King of NoMansLand

You mean this?

Point3d apex = YouTellMe; List<Point3d> rest = Ditto;

List<Point3d> ConnLines = new List<Point3d>();

foreach(Point3d p in rest){

Line line = new Line(apex, p);

ConnLines.Add(line);

}

Q2 is ambiguous: what are exactly the rules? Get the first from List1 and then the first from List2 ... etc OR "join" the Lists with respect the "local" enumeration? If yes then:

List<Point3d> SumPts = new ... blah, blah

SumPts.AddRange(List1); // and 2 and 3 until the end of Time

But you should use DataTrees instead of Lists1,2,3,N. For instance and for a tree with one dimension:

foreach(GH_Path path in SomeTree.Paths()){

List<Point3d> tmp = SomeTree.Branch(path).ToList();

SumPts.AddRange(tmp);

}

Permalink Reply by Zhengyu Xue on February 26, 2016 at 1:49am

Dear Friend,

I have a riddle for you: what opens and closes at the same time?

It's been a long time since our last contact. During the past month, I made a plugin written in Vb , and with your help I finished my parametric model with a lot of components written by C#.

Now I am struggling with optimisation (shape ,pretension, cross section, mass). I want to do it with programs fully embedded in Grasshopper environment, thus I turned to Karamba, Galapago and Octopus.

I have added a new discussion about applying pretension for cables in Karamba. If you have experience with this software, I hope you could have a look at the following link.

http://www.grasshopper3d.com/forum/topics/request-diagnosis-about-a...

Best ,

Zhengyu

Permalink Reply by peter fotiadis on February 26, 2016 at 4:04am

Er... hmm ... alas: I have no idea about Karamba and Octopus.