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:
…
greatly appreciate it!!
You can write the number of the question and write your answer next to it, example:
1) a
2) c
3) a) Washington University in St. Louis
4) 2 weeks (1week+1week shipping)
5) 130
6) b
7) b
The survey questions are as follows:
1)
Did you 3D print before?
5)
How much did it cost (in dollars)?
a.
Yes, for a school project
a.
Between 20 & 50
b.
Yes, for a personal project
b.
Between 50 & 80
c.
Between 80 & 120
2)
Print size
d.
Please specify if otherwise: _____ dollars
a.
Between 2 & 6 cubic inches
b.
Between 6 & 12 cubic inches
6)
Do you think the price was expensive?
c.
Between 12 & 20 cubic inches
a.
Not at all
d.
Please specify if otherwise: ____cubic inches
b.
A little bit expensive
c.
Very expensive
3)
Where did you print your object?
a.
School
7)
Were you satisfied with the printed object?
b.
Outside school: _________________
a.
Yes, it was a great print without problems
b.
Not bad, some issues
4)
How long did it take to print?
c.
I was not satisfied, very bad quality
a.
___ days
b.
___ weeks
Thank you very much to all!!
PS: If you did many 3D prints, you can post multiple answers.
Wassef…
whole design intent, but this is what Inventor is good at. The way it packages bits of 'scripted' components into 'little models' that can be stored and re-assembled is central to MCAD working.
The Inventor model shown is almost 5 years old. We don't model like that any more, however it does offer a good idea of general MCAD modeling approaches.
iParts is useful in certain situations, it could've been useful in the above model, its usefulness is often in function of the quantity of variants/configurations.
So much is scripted in GH, maybe it should also be possible to script/define/constrain/assist the placement/gluing of the results?
...
Starting point: I think we are talking across purposes. AFAIK, the solving sequence of GH's scripted components is fixed. It won't do circular dependencies... without a fight. The inter-component dependencies not 'managed' like constraints solvers do for MCAD apps.
Components and assemblies are individual files in MCAD.
Placement of these within assemblies in MCAD is a product of matrix transforms and persistent constraints. There is no bi-directional link, the link is unidirectional (downflow only), because of the use of proxies.
Consequently, scripting the placement of components is irrelevant in GH, unless you decide that each component needs to be contained in its own separate file.
This also brings up the point that generating components and assemblies in MCAD is not as straightforward. In iParts and iAssemblies, each configuration needs to be generated as a "child" (the individual file needs to be created for each child) before those children can be used elsewhere.
You notice the dilemma, if you generate 100 parts, and then you realize you only need 20, you've created 80 extra parts which you have no need for, thus generating wasteful data that may cause file management issues later on.
GH remains in a transient world, and when you decide to bake geometry (if you need to at all), you can do that in one Rhino file, and save it as the state of the design at that given moment. Very convenient for design, though unacceptable for most non-digital manufacturing methods, which greatly limits Rhino's use for manufacturing unless you combine it with an MCAD app.
One of the reasons why the distributed file approach makes perfect sense in MCAD, is that in industry you deal with a finite set of objects. Generative tools are usually not a requirement. Most mechanical engineers, product engineers and machinists would never have any use for that.
The other thing that MCAD apps like Inventor have, is the 'structured' interface that offers up all that setting out information like the coordinate systems, work planes, parameters etc in a concise fashion in the 'history tree'. This will translate into user speed. GH's canvas is a bit more freeform. I suppose the info is all there and linked, so a bit of re-jigging is easy. Also, see how T-Flex can even embed sliders and other parameter input boxes into the model itself. Pretty handy/fast to understand, which also means more speed.
True. As long as you keep the browser pane/specification tree organized and easy to query.
:)
Would love to understand what you did by sketching.
I'll start by showing what was done years ago in the Inventor model, and then share with you what I did in GH, but in another post.
Let's use one of the beams as an example:
We can isolate this component for clarity.
Notice that I've highlighted the sectional sketch with dimensions, and the point of reference, which is in relation to the CL of the column which the beam bears on. The orientation and location of the beam is already set by underlying geometry.
Here's a perspective view of the same:
The extent of the beam was also driven by reference geometry, 2 planes offset from the beam's XY plane, driven by parameters from another underlying file which serves as a parameter container:
Reference axes and points are present for all other components, here are some of them:
It starts getting cluttered if you see the reference planes as well:
Is I mentioned earlier, over time we've found better ways to define and associate geometry, parameters, manage design change, improving the efficiency of parametric models. But this model is a fair representation of a basic modeling approach, and since an Inventor-GH comparison is like comparing apples and oranges anyways, this model can be used to understand the differences and similarities, for those interested.
I haven't even gotten to your latest post yet, I will eventually.…
Added by Santiago Diaz at 10:36am on February 26, 2011
he picture (4).
Previously, I had a problem with generating intersections between the two directions of the beams, but a colleague helped me by extending beams, so there was no problem with lines of intersection. But this solution has generated curl (5) at the highest vertex geometry, which I ignored in order to repair it before printing, perhaps this mean my problem with my beam spread properly. Only when the beams is 19, does not jump no problem, but I still can not distribute them properly.
(1)
(2)
(3)
(4)
(5)
I tried to show as simply as possible by removing or signing my code in GHX file.
Thank you in advance for your help
…
edit 29/04/14 - Here is a new collection of more than 80 example files, organized by category:
KangarooExamples.zip
This zip is the most up to date collection of examples at the moment, and collects t
Introduction to Grasshopper Videos by David Rutten.
Wondering how to get started with Grasshopper? Look no further. Spend an some time with the creator of Grasshopper, David Rutten, to learn the
This blog post is a rough approximation of the lecture I gave at the AAG10 conference in Vienna on September 21st 2010. Naturally it will be quite a different experience as the medium is quite…
Added by David Rutten at 3:27pm on September 24, 2010