# How do I make a funnel roof structure using grasshopper

hi I’m new to grasshopper and have recently done a course on the basics however I’m struggling to produce this type of structure

I’m aware I can create the funnel shape in rhino however I want to produce the most efficient structure possible therefore I believe if I use grasshopper to design it parametrically this will give me the most optimum solution eg for column placement, roof height etc. I think this can be done using kangaroo?

any help or advice would be greatly appreciated!

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In an ideal word (I would strongly suggest to start that kind of stuff with classic quad meshes and an ortho topology (grid like) … later on you can exploit other topologies):

1. Define a grid and on the fly - interactively - define the flat modules (so to speak) and the modules that yield cones - that compose the “columns” (This is the core of the matter … but … you can’t do it without code).
2. Define a mesh in the flat modules, the cones and the connecting rings (see images below) in such a way that K2 could start with an input Mesh as uniform as possible (you can do that with native components but is a bit tricky). In your pic above the “columns” are a pit pathetic (lack density in the conic part).
3. Then relax the mesh via K2 using some anchor policy (that’s a big thing). Have in mind that if the input is bananas (see 2) expect a bananas output as well: K2 can’t fix a bad mesh. Depending on the spring values (and maybe some unary force [gravity]) you can obtain various results: good, bad, ugly etc etc. On a higher level of relaxation control the columns may have different spring values than the flat parts and/or different unary forces.
4. Then comes the real pain: what to do with these “relaxed” lines (Mesh edges). This is not a task for a novice by any means (if you want some real-life solution, even an Academic real-life one) - so forget it completely for the moment. In fact you can’t do that without code.

For instance:

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Thank you for your reply Peter, really appreciate it. Is there any chance you could explain in further detail? This is all really new to me so I’m unfamiliar with a lot of the stuff you mentioned…

Well … let’s start from A: get fully the gist of K2 (what is that thing, what can [and can’t] do and how). This requires 1 to 6 months. Then go to B: get familiar with ways (forget the interactive freaky part mentioned above) to define a grid, a mesh on the grid modules, a cone (in fact several), a grid on the cones … and what happens between the top lip of the cones and the boundary of the corresponding module (mentioned as “connecting rings” above).

PS: maybe by some miracle you are familiar with C# ? (or have future plans to start coding?).

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Unfortunately, I don’t have that much time my project is due in a few weeks! Is there a simpler way of doing this?

If the project includes designing some sort or “realistic” envelope on top (that doesn’t leak) … better find some other topic of interest (life sucks).

Other than that … well … I have at least 100 C#'s (i.e. an alien “component” that is not a component nor is a compiled add-on nor is a cluster) that do things like these … but what could the the benefit of using such a solution? And if this is an Academic project - of some sort - how you could explain to your tutor the existence of a given C#?

But hope dies last: is more than possible that someone else (or even Daniel - the K2 man) can provide some sort of example/demo using native GH components (that your tutor could understand).

On the other hand: here’s a deal.

Try to do that with components. I.e. forget the interactive part and do a grid that has in random (or not) places the “columns” - then do a mesh out of all these with variable “resolution”. So we have on hand a homogenous mesh to send to K2 (the better the start mesh the better the results).

If you do that, post the def here and I can provide some hints upon how to relax that thing (or see the attached). The result may be kitsch or good … er … depending on the K2 parameter values used. For instance this is 100% kitsch and 100% unrealistic (is using a variety of options with regard the anchors: all naked vertices, some naked vertices, some dogs, some cats etc etc):

On the other hand the attached (using a boundary and some random circles for the columns [plus MeshMachine]) is the only vault like thing available that is not carried over solely via code. A hybrid def using some native components (done for training some people in the practice for learning C#).

K2_VaultLike_V1.gh (138.3 KB)

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thank you for your help! i’ll see what i can do

Hi again Peter!
do you know anything about karamba3d and how I can add that to the model?

Nothing at all: I use solely Bentley Systems apps for AEC BIM matters.