Cellular structures in Rhino

Dear all,
I am sending this email in order to ask your opinion about modelling cellular structures in rhino.The concept of my model is a cellular structure that consists of 2 types of polyhedra cells,more specific the Weaire and Phelan structure.https://en.wikipedia.org/wiki/Weaire–Phelan_structure

The size of each cell is 10mm * 7mm.The whole size of the model that I want to create is a box of 160mm * 160mm * 100mm that is consisted by 900-1000 polyhedra. Moreover this model is going to be 3d printed and imported in a software fro thermal simulations in order to test its performance.First I tried to create a model that it is possible to be 3d printed and has some transformations in order to distinguish for the printer the solid and void part.Although I started with creating blocks and groups and using the array and copy command there are a few problems that I am facing.First the file is “heavy” and not easy to manipulate.Secondly as a next step for my model I want to manipulate the size of the polyhedra in order to create a variety of sizes.For example create smaller sizes of polyhedra at the edges of the model or at the planes of the box and larger polyhedra in the middle of the box.In addition this traansition from smaller to bigger size in a further step I want to consist the transition from the shape of polyhedra to shape of shperes.As a result I will have a component that distributes different sizes of polyhedra and spheres.Do you have any suggestions on how to proceed?Is modeling in rhino a good option because until now I have spent hours to built this model and it takes hours also to manipulate.I was thinking to try to use grasshoper 3d as a second option however I am not familiar with the software and think that it might take longer to achieve my goal.I am looking forward for your suggestions.I have also attached snapshots of my model in this mail.Thank you in advance

Kind regards
Valentini

The advantage of using Grasshopper will be that the file is much easier to manipulate and that you will only “bake” the objects once you have the you want configuration set. It will also allow you to preview your different configurations rapidly. On the other hand, to produce a “solid” model from many overlapping solids will still require some computation-intensive Boolean operations. You may however be able to eliminate all but the outer layer objects (either manually or with Grashopper) which will make the procedure much “lighter”.

Grasshopper is still a programming interface though (albeit visually-driven), so there will be a learning curve there.

–Mitch

Sounds like you need to test-drive Intralattice:


http://intralattice.com/overview/

Dear Mitch,

Thank you for your direct response.I would like to ask also whether it is feasible to try this transition from one pattern to the other because I am aware that it is possible to create a gradient of one shape and create a deformation of the shape,however I do not know if it is possible to try to manipulate the size of two patterns in the same model.Thank you in advance

Kind regards
Valentini

Dear Wim,
I am aware of intrallattice plug in grasshoper however,I think that intralattice is mainly for open cell and lattice structures,whereas I want to create a closed cell structure.Correct me if i am wrong.Thank you in advance

Kind regards
Valentini

Well, I see your procedure (according to your image) as a 3D array of polyhedra according to a grid. It is possible to easily create that grid (resizable as well) and then distribute objects to it in a uniform or non-uniform fashion. For example it is possible to apply a noise-type filter to a scale value for each polyhedron to create objects of varying random sizes from the same base object. You should be able to interweave any number of patterns as you like. The definition could get pretty complex, but it seems that what you want to do is well within the capability of Grasshopper - whose capabilities with a skilled operator are frankly enormous.

–Mitch

Dear Mitch,
Thank you for your response

Kind regards
Valentini

No, you are correct. I didn’t pay enough attention when I read your post the first time and I didn’t read the Wikipedia article.

So this model will basically be completely solid? Are you 3d printing in different materials at the same time?

My purpose is to create air pockets inside these closed cellular structures.The cells consist of polyhedra and spheres.In addition there is a variation in sizes,for example in the edges and the surface there will be smaller air pockets and smaller polyhedra,whereas in the core of the model there suppose to be created larger cells,and probably a transition from polyhedra to spheres.
There are two options first create a gradient transition in size and shape,whereas in the second there are two sizes 7mm and 10mm size of spheres and they are clearly divided into layers.What I want to do is a combination of both options.So for example.Select 3 or 4 types of cells maybe more but still defined number and then try to position in my model according to certain domains.For example thermal parameters or structural parameters

The 3d printing process is going to be only with one material at this moment.However I reached i-materialize and I 've been told that there is no option of printing two materials at the same time,so using two extruders,unfortunately.

Really interesting! Thanks for the insight!

You are welcome,do you maybe have a suggestion on how I can approach the challenge by using rhino or grasshoper.Thank you in advance

Kind regards
Valentini