e matching with a dedicated component which creates combinations of items. You can find the [Cross Reference] component in the Sets.List panel.
When Grasshopper iterates over lists of items, it will match the first item in list A with the first item in list B. Then the second item in list A with the second item in list B and so on and so forth. Sometimes however you want all items in list A to combine with all items in list B, the [Cross Reference] component allows you to do this.
Here we have two input lists {A,B,C} and {X,Y,Z}. Normally Grasshopper would iterate over these lists and only consider the combinations {A,X}, {B,Y} and {C,Z}. There are however six more combinations that are not typically considered, to wit: {A,Y}, {A,Z}, {B,X}, {B,Z}, {C,X} and {C,Y}. As you can see the output of the [Cross Reference] component is such that all nine permutations are indeed present.
We can denote the behaviour of data cross referencing using a table. The rows represent the first list of items, the columns the second. If we create all possible permutations, the table will have a dot in every single cell, as every cell represents a unique combination of two source list indices:
Sometimes however you don't want all possible permutations. Sometimes you wish to exclude certain areas because they would result in meaningless or invalid computations. A common exclusion principle is to ignore all cells that are on the diagonal of the table. The image above shows a 'holistic' matching, whereas the 'diagonal' option (available from the [Cross Reference] component menu) has gaps for {0,0}, {1,1}, {2,2} and {3,3}:
If we apply this to our {A,B,C}, {X,Y,Z} example, we should expect to not see the combinations for {A,X}, {B,Y} and {C,Z}:
The rule that is applied to 'diagonal' matching is: "Skip all permutations where all items have the same list index". 'Coincident' matching is the same as 'diagonal' matching in the case of two input lists which is why I won't show an example of it here (since we are only dealing with 2-list examples), but the rule is subtly different: "Skip all permutations where any two items have the same list index".
The four remaining matching algorithms are all variations on the same theme. 'Lower triangle' matching applies the rule: "Skip all permutations where the index of an item is less than the index of the item in the next list", resulting in an empty triangle but with items on the diagonal.
'Lower triangle (strict)' matching goes one step further and also eliminates the items on the diagonal:
'Upper Triangle' and 'Upper Triangle (strict)' are mirror images of the previous two algorithms, resulting in empty triangles on the other side of the diagonal line:
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lla progettazione parametrica e le tecniche di modellazione algoritmica per la generazione di forme complesse
___________________________________________________________________________________
luogo:
Sala meeting Hotel Mercure Milano Centro Piazza Oberdan 12 – 20129 MILANO
Scadenza iscrizioni: 12 Novembre 2011 – ore 15.00
___________________________________________________________________________________
info e prenotazioni:
Le Penseur (coordinamento formazione)
info@lepenseur.it
081 564 21 84
347 548 71 78
quote di partecipazione e programma (formato PDF)
ulteriori informazioni sui corsi PLUG > IT
___________________________________________________________________________________
PROGRAMMA DEL CORSO
GIORNO_01
10.00 – 10.30: presentazione workshop
10.30 – 11.30: introduzione alla progettazione parametrica: teoria, esempi, casi studio
11.30 – 13.00: Grasshopper: concetti base, logica algoritmica, interfaccia grafica
13.00 – 14.00: break | lunch
14.00 – 16.00: nozioni fondamentali: componenti, connessioni, data flow
16.00 – 18.00: esercitazione
GIORNO_02
10.00 – 12.00: funzioni matematiche e logiche, serie, gestione dei dati
12.00 – 15.00: analisi e definizione di curve e superfici
GIORNO_03
10.00 – 12.00: definizione di griglie e pattern complessi
12.00 – 13.00: trasformazioni geometriche, paneling
13.00 – 14.00: break | lunch
14.00 – 16.00: esercitazione
16.00 – 18.00: attrattori, image sampler
GIORNO_04
10.00 – 13.00: data tree: gestione di dati complessi
13.00 – 14.00: break | lunch
14.00 – 15.00: digital fabrication: teoria ed esempi
15.00 – 18.00: nesting: scomposizione di oggetti tridimensionali in sezioni e posizionamento su piani di taglio per macchine a controllo numerico CNC…
up structural systems in the parametric environment of Grasshopper. Participants will be guided through the basics of analysing and interpreting structural models, to optimisation processes and how to integrate Karamba3d into C# scripts.
This workshop is aimed towards beginner to intermediate users of Karamba however advanced users are also encouraged to apply. It is open to both professional and academic users.
Course Fee:
Professional EUR 750 (+VAT)
Educational EUR 375 (+VAT)
Course Outline
Introduction & Presentation of project examples
Optimization of cross sections of line based and surface based elements
Geometric Optimization
Topological Optimization
Structural Performance Informed Form Finding
Understanding analysis algorithms embedded in Karamba and visualising results
Complex Workflow processes in Rhino3d, Grasshopper3d and Karamba3d
Places are limited to a maximum of 10 participants with limited educational places. A minimum of 4 places are required for the workshop to take place.
The workshop will be cancelled should this quota not be filled by May 31st.
The workshop will be taught in English. Basic Rhino and Grasshopper knowledge is recommended. No knowledge of Karamba is needed.
Participants should bring their own laptops with either Rhino5/Rhino6 and Grasshopper3d installed. A 90 day trial version of Rhino can be downloaded from Rhino3d.
Karamba ½ year licenses for non-commercial use will be provided to all participants.
…
up structural systems in the parametric environment of Grasshopper. Participants will be guided through the basics of analysing and interpreting structural models, to optimisation processes and how to integrate Karamba3d into C# scripts.
This workshop is aimed towards beginner to intermediate users of Karamba however advanced users are also encouraged to apply. It is open to both professional and academic users.
Course Fee:
Professional EUR 750 (+VAT)
Student EUR 375 (+VAT)
Course Outline
Introduction & Presentation of project examples
Optimization of cross sections of line based and surface based elements
Geometric Optimization
Topological Optimization
Structural Performance Informed Form Finding
Understanding analysis algorithms embedded in Karamba and visualising results
Complex Workflow processes in Rhino3d, Grasshopper3d and Karamba3d
Places are limited to a maximum of 10 participants with limited educational places. A minimum of 4 places are required for the workshop to take place.
The workshop will be cancelled should this quota not be filled by October 15th.
The workshop will be taught in English. Basic Rhino and Grasshopper knowledge is recommended. No knowledge of Karamba is needed.
Participants should bring their own laptops with either Rhino5/Rhino6 and Grasshopper3d installed. A 90 day trial version of Rhino can be downloaded from Rhino3d.
Karamba ½ year licenses for non-commercial use will be provided to all participants.
…
ive 'correct' normal.
Non-normalized cross products is effectively weighting face normals by area, and is fast and simple, so we put that one as the default.
In some cases normalizing the cross-products improves the result, but not always.
Another option is to weight by angles, though this is computationally slightly more expensive, so might not be ideal for real-time updates on large meshes.
As an example, here is a mesh with a 90° corner, and uneven meshing on the 2 sides.
The arrows show:
0- Area weighted (non-normalized cross products)
1- Angle weighted
2- Normalized cross-products
Here the angle-weighted normal is the one at 45°, which is intuitively the 'best' one in this case.
These 3 seem to be the most commonly used, but there are many other possible definitions of normals - such as inverse-area weighted, mean curvature, etc...
I think really what would be best would be to put a few of these into Plankton, and include an optional argument in GetNormal for selecting which one you need for a particular application.
Pull requests welcome if you feel inspired to add this!
http://meshlabstuff.blogspot.co.uk/2009/04/on-computation-of-vertex-normals.html
http://steve.hollasch.net/cgindex/geometry/surfnorm.html…
us allows Grasshopper authors to stream geometry to the web in real time. It works like a chatroom for parametric geometry, and allows for on-the-fly 3D model mashups in the web browser. Multiple [Grasshopper] authors can stream geometry into a shared 3D environment on the web – a Platypus Session – and multiple viewers can join that session on 3dplatyp.us to interact with the 3D model. Platypus can be used to present parametric 3D models to a remote audience, to quickly collaborate with other Grasshopper users, or both!
You can down load the Grasshopper plugin at food4rhino, and visit 3dplatyp.us to view your geometry on the web. This first round of Alpha testing will run for two weeks, until April 24 2014, after which the Grasshopper components will not solve.
We are very interested in hearing feedback from the community while the project is still in the prototyping stages of development. Please use the comments on this discussion to ask questions, suggest ideas, report bugs, etc. We are planning on rolling out another public alpha release or two this Spring, depending on how this first one goes, in advance of our Technology Symposium and Hackathon in New York.
Check out our getting started video below, and enjoy!
…
e rod with circular section (no goals allow for controlling torsion for what I know). The rods are set with two options, with straight rest position or the (initial) bent one. The calibration integrated with the model is more about giving a scale between the forces rather than the will to accurately simulate them (at the moment). Anyway, I am trying to do it on a macro scale, instead of a micro, with elements which are rather thin.
The system at the moment is not stable. In fact, besides the rods' characteristics is quite fundamental to keep them planar when they intersect. I am lacking something but also probably missing some parameters. In the script, there are two goals to define this: impose 90° between vertical and horizontal, as well as between these and a normal to their intersection. For my understanding, angle goal works tri-dimensionally without a preferred plane and this (hopefully) should address it.
Just wondering if anyone can give me a hint on this. After this step, it would be great to understand if the system can get out of its plane (through a pull force out of its plane, simulated in the script through point loads in the joints). I am still not entirely sure about the possibility of doing this. By looking at how other auxetic patterns have been used to generate freeform surfaces, I am giving it a try.
Thank you
Claudio
PS: I noticed also this post and this, really interesting. I see the problematic over the stability and the necessity to separate the states with an energetic hill in the first, as well as some potential in using auxetics in the latter.…
opening a simple file with 30 curves being lofted took like 2 minutes to complete and Rhino crashed afterwards saying:"Windows is out of memory and Rhino will close after you click ok."evethough I still had 7GB of free physical memory and my page file is set also to 16 GB just to be shure...I then switched to Rhino 5.0 Version 5 SR14 64-bit (5.14.522.8390, 05/22/2017) which also had big problems to display the lofted surface. It was unresponsive after loading the file for a minute and a half and then it normally displayed the lofted surface. Every move of camera takes at least 10 seconds to update, but at least it runs. GH profiler says the loft took only 12 ms (90%).
So I'm suspected my graphics card, because the Windows are just three weeks from a clean install. I've also updated my Graphics Driver from the stock Windows one to Intel HD one, but nothing changed.Is there something I'm missing??? What can I try next?My specs:CPU: i5-3320M @ 2.60 GHzRAM: 16 GBGPU: Intel HD Graphics 4000, driver: 07.04. 2017, version 10.18.10.4653
…
Added by Šimon Prokop at 10:39am on October 21, 2017
ails.
Some word about the mesh... (see Image_01)
I took a flat 4 points NURBS surface as imput (very easy, it defines the total area of my pavilion) and some points (that defines the contact with the ground).
Then I extracted a grid of points from the NURBS (Surface_Util_Divide surface) and compared 'em with the contol points, in order to associate to each grid's point its own attractor (Vector_Point_Closest Point).
Than I moved the points down. I used the distance from each point to its attractor (inverted) as amplitude for the vector of the movement, in order to say: the nearer you are to the control point, the more intense your movement will be. During this operation I've passed the distances' data list into a graph mapper (Params_Special_Graph Mapper), in order to regulate in a very intuitive and interactive way the shaping of my canopy.
At the end of the process I asked GH for a simple Delaunay mesh (Mesh_Triangulation_Delaunay Mesh). It's a very cool command, I believe!!!
Ok, now some word about the component, it's design and it's repetition/adaptation to the mesh...
(see Image_02)
I took the mesh and extracted components on first and faces's information on second. Then I selected and separated the vertexes (1°, 2°, 3°) of each triangular face into threee well defined list.
Then I re-created the triangles' edges. Please pay attention because it's not the same if you use output information from Delaunay components, because here we need a justapposition of edges where triangles touches each others.
After this work I joined the edges and found their centroid. At the same time I found the mid point of each edge.
Now the component... (see Image_03)
It' a little bit longer to describe: I'll try to be synthetic.
Substantially it is a loft from a curve to a point, repeated three times for each triangle (Surface_Freeform_Extrude Point). The point is an elevation of the centroid of the triangle (you can choose if the exstrusion has a single height or it's related to an attractor. In my case it was fixed). The curve is combination of things. There's an arch, which starts on the edge (there's an offset from the corner) end terminates on the same edge (on the other side, obviously). While it's generation the arch passes through a third point which belong to another segment. This last connects the mid point of the original edge (base triangle) with the centroid. The result is a kind of polyline, with two segments and an arch. If you go back to the image of the component that I posted probably you'll understand what I'm saying better than with the definition.
The posit…
up structural systems in the parametric environment of Grasshopper. Participants will be guided through the basics of analysing and interpreting structural models, to optimisation processes and how to integrate Karamba3D into C# scripts.
This workshop is aimed towards beginner to intermediate users of Karamba3D however advanced users are also encouraged to apply. It is open to both professional and academic users.
Earlybird (until May 10):
Professional EUR 750 (+VAT)
Educational EUR 375 (+VAT)
Course Fee:
Professional EUR 825 (+VAT)
Educational EUR 415 (+VAT)
Course Outline
Introduction & Presentation of project examples
Optimization of cross sections of line based and surface based elements
Geometric Optimization
Topological Optimization
Structural Performance Informed Form Finding
Understanding analysis algorithms embedded in Karamba and visualising results
Complex Workflow processes in Rhino3d, Grasshopper3d and Karamba3d
Places are limited to a maximum of 10 participants with limited educational places. A minimum of 4 places are required for the workshop to take place.
The workshop will be cancelled should this quota not be filled by May 31st.
The workshop will be taught in English. Basic Rhino and Grasshopper knowledge is recommended. No knowledge of Karamba3D is needed.
Participants should bring their own laptops with either Rhino5/Rhino6 and Grasshopper3d installed. A 90 day trial version of Rhino can be downloaded from Rhino3d.
Karamba3D ½ year licenses for non-commercial use will be provided to all participants.
…