well, very similar input data must result in wildly different hashes. For example, imagine we have an algorithm which computes hashes of text, and the hashes it computes are all numbers between 0 and 999. We then apply this algorithm to a piece of text:
"When Spring comes back with rustling shade" = 385
So far so good. Now imagine we change the text slightly, for example by removing a single "l":
"When Spring comes back with rusting shade" = 973
Minor change -> very different hash. There are of course way more unique texts than there are numbers between 0 and 999. This must therefore mean that a lot of text will result in the same hash. For example "When Spring brings back blue days and fair." may also result in a hash of 385. Because of the pigeonhole principle, there is nothing to be done about this.
Now for the tricky bit. Hashes are often used to validate executable code. Say your friend James at MI6 sends you a small program that will allow you to eavesdrop on Angela Merkel, and -over the phone- he tells you the hashcode for that application. You can then hash the application yourself, verify that it indeed results in the same hashcode and then you know you can trust the executable.
But now Jack from the FBI intercepts the email and adds a few sneaky lines of code to the original application allowing him to determine from your internet search history with up to 95% accuracy whether you like extra cheese on your pizza. The application has now been tampered with, it can no longer be trusted and you should be able to figure this out as it will no longer result in the same hash code.
But wait! Some hashing algorithms are more secure than others. MD5 is now officially considered to be 'hacked' and it is no longer recommended for doing naughty spying. Specifically, Jack will be able to inject his own code in such a way that it does not result in a different hash. Instead, the SHA family of hashers are to be used, as it is not yet known how to trick these hashers.
This is where the problem comes in, because apparently the US government has forcefully disabled the use of MD5 for all purposes. This is a shame because I use it to quickly compare bitmap icons for identicalness so I only have to store an icon in memory once. There is no security hole due to this, because I'm not hashing secure data. MD5 is somewhat faster than SHA, and since I have to hash several hundred icons on Grasshopper start, I opted for the faster one.
(Very) long story short; you're hosed. Grasshopper uses MD5; USgov does not like; Grasshopper does not run on USgov computers.
I'll do some testing to see if I can switch to SHA and then we can see whether or not that solves the problem. This however will take a while as I'm going on a business trip next week and have yet to prepare my presentations.
--
David Rutten
david@mcneel.com…
Added by David Rutten at 12:06pm on March 31, 2014
answer further on Friday.
The "ghdoc" variable and rhinoscriptsyntaxThe ghdoc variable is provided by the component if you select it as "target".You might ask yourself: "why do we need it"?Its use comes from the very design of the established RhinoScript library. This library is imperative, which means it is build from a set of procedures or functions that act on various geometrical types. Additionally, there is one level of indirection: most of the time, the user does not work with the geometry itself in the variable, but rather with Guid of geometry that is present in a document. This is exactly what ghdoc is: it is the document that the RhinoScript library always implicitly targets with all AddSomething() calls (for example, AddLine()).
Based on this comment...RhinoScript use within GhPython may be less idealThat comment is from a previous version of this component that did not have the ghdoc yet.With the ghdoc variable, the standard Rhino document target of RhinoScript is replaced, therefore we can use Grasshopper while leaving the Rhino document unchanged. This saves uncountable Undo's, and makes it easy to structure ideas through the definition graph
...is the rhinoscriptsyntax target irrelevant if using solely RhinoCommon classesYes. If you create class instances (objects), you will need to create also your own collection objects to store them (mostly lists, trees). You can imagine the ghdoc as being an alternative to them, just that you do not access data by index (number), but by Guid. So you can use the RhinoScript or the RhinoCommon libraries independently or mix them. The RhinoScript implementation in Rhino is open-source and is all written in RhinoCommon. Also the ghdoc implementation is open-source, and is here.
RhinoScript and/or RhinoCommon objects which are not recognized as valid Grasshopper geometryYes, sure, Grasshopper handles only a portion of all available types. Basically, unhandled types are all the types that do not exists in the 'Params' tab. For example, there is no textdot and no leader, so on line 149 there is a throw statement and all TextDot calls (about line 350) are commented out. When/if Grasshopper one day will support these types, these calls will be implemented.
DataTreeHere is a small sample. However, I think that 80% of the times it is not necessary to program for DataTrees, as the logic itself can be applied per-list and Grasshopper handles list-iteration.
I hope this helps,
- Giulio_______________giulio@mcneel.comMcNeel Europe…
ort and export from the images below and also from the HELP file of DB in attachments (Page 71: Importing Geometric Data; Page 78-80: Import 3 - D CAD Data). In their HELP file, they mention about "import geometric data".
However, regarding the input of schedules, loads, constructions and etc., DB normally uses "Component " and "Template" (Page 29: Templates And Components; Page 591: Templates; Page 533: Components). "Templates" are databases of typical generic data, including Activity templates, Construction templates, Glazing templates, Facade templates, HVAC templates, Location Templates, and etc. "Component " are databases of individual data items (e.g. a construction type, material, window pane).
Both "Component " and "Template" are allowed to be imported and exported by using "Import / Export library data" command (.ddf format - DB Database File; Page 734: Import Components/Templates, Export Components/Templates). DB also allows us to build up our own libraries of templates and components (Page 731: Library Management; Page 733: Template Library Management).
In order to import both geometric information and other information related to schedules, loads, constructions and etc. from GH to BD, we supposed the following two ways:
1. GH(HB+GB) --> gbXML (both geometric and "Component " and "Template" information) --> DB
This is the way we most prefer. We did see information related to schedules, loads, constructions encoded in the gbXML file generated by GB, but still do not know the reason why DB did not take this information (I also mentioned this in Q6 within the gh file). We assume this might because the gbXML file we create encodes the schedules based on a different template / schema than the one DB expects. We also post this question to the DB forum for help.
(http://www.designbuilder.co.uk/component/option,com_forum/Itemid,25/page,viewtopic/p,13755/#13755)
2. GH(HB+GB) --> gbXML (geometric information only) + .ddf ("Component " and "Template" information only) --> DB
If the first way doesn't work and DB only takes geometric information from the gbXML, then we might think of the other way - generating the .ddf files from GH(HB+GB) to pass the schedule, load and construction information to DB.
I was wondering if it is feasible for HB and GB to have this function? And what is your suggestion to achieve this?
In addition, we notice that DB can export XML files (not gbXML), so we are trying to figure out if DB also accepts / reads the XML file. If so, we might be able to convert the gbXML (with both geometric and schedule information) to XML. What do you think about that?
Thank you again for all your help!
Best,
Ding
DB import
DB export
Template libraries
Component libraries
…
y using the Honeybee_Update Honeybee component.
The video below (best viewed in full-screen mode) provides an idea of what these components are capable of being used for:
The video below shows how these components can be used in an existing Honeybee project (for additional links please open this video in youtube):
I have uploaded two examples as Hydra files that show how these components can be used for grid-point and image-based simulations:
Example1 : Grid Point Calculations
Example2: Image based simulation
Finally, a more esoteric application is demonstrated in this video:
These components are still in the beta-testing stage. Some of the limitations of the components are:
1. Only Type C photometry IES files are supported at present.
2. Rhino is likely to get sluggish if there are too many luminaires (i.e. light fixtures) present in a scene.
3. Due to the spectral limitations of the ray-tracing software (RADIANCE), simulations involving color mixing might not be physically realizable.
Additional details about photometric and spectral calculations are probably an overkill for this forum. However, I'd be glad to answer any related questions. Please report any bugs or request new features either on this forum or on Github.
Mostapha, Leland Curtis, Reinhardt Swart and Dr. Richard Mistrick provided valuable inputs during the development of these components.
Thanks,
Sarith
Update 16th January 2017:
An example with some new components and bug fixes since the initial release announcement can be found here
…
Introduzione a Grasshopper", il primo manuale su Grasshopper.
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I corsi PLUG IT nascono dalla volontà di promuovere le nuove tecnologie digitali di supporto alla progettazione e condividere il know-how maturato attraverso ricerca, collaborazione con i più importanti studi di architettura e pubblicazioni internazionali.
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Verranno introdotte le nozioni base di Grasshopper approfondendo le metodologie della progettazione parametrica e le tecniche di modellazione algoritmica per la generazione di forme complesse. Il corso è rivolto a studenti e professionisti con esperienza minima nella modellazione 3D e si articolerà in lezioni teoriche ed esercitazioni.
. Argomenti trattati:
- Introduzione alla progettazione parametrica: teoria, esempi, casi studio - Grasshopper: concetti base, logica algoritmica, interfaccia grafica - Nozioni fondamentali: componenti, connessioni, data flow
- Funzioni matematiche e logiche, serie, gestione dei dati - Analisi e definizione di curve e superfici
- Definizione di griglie e pattern complessi - Trasformazioni geometriche, paneling - Attrattori, image sampler
- Data tree: gestione di dati complessi - Digital fabrication: teoria ed esempi - Nesting: scomposizione di oggetti tridimensionali in sezioni piane per macchine CNC
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Verrà rilasciato un attestato finale.
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Ulteriori info e programma completo su: www.arturotedeschi.com e su www.edizionilepenseur.it…
th one element which is a list of 10 numbers?
I can flatten it and get (I think) a list of 10 elements (even though when I hover over the output of "Flatten" it says "Tree(T) as tree"). I'm surprised I can flatten at all what would appear to common sense to be a simple list of 10 numbers.
I'm hoping that if I can get this answered it will become obvious why we have trees of lists rather than just lists of lists as you would in most computer languages. That's my real goal - to understand the purpose of adding what seems like an unnecessary complication - trees - to the concept of lists in GH. It seems to me as though a "tree" is just a list of other "trees" until you get to the leaves where you can have "lists" which are identical to trees but can have something other than a tree in them. Whether you can have lists of trees or trees with no lists I'm unclear on. Do the leaves of trees have to be lists? Do lists have to be contained in trees? It would appear from the series example where a tree is produced for no obvious reason to contain the list that this is the case but given that you can flatten it, I guess not - or is the "List" I see in the param viewer just another type of "tree"?
I've found many tutorials that talk about how to manipulate trees and lists and I've managed to get along fairly well with them so far, but nothing seems to explain the reasoning behind the existence of trees and the philosophy for how and when they should be used and when lists should/could be used and precisely what the difference is between them.
Sorry to be long winded but I'm so confused!
Darrell Plank
P.S. I've seen David Rutten's diagram with the colored leaves in Grasshopper Primer 2 and that seems helpful. It would appear that trees can only have lists at their leaves and lists can't have trees although I'm not sure that it comes out and says that directly but at least there are no examples of this shown in his tree diagram. I thought I had it down pretty much so decided to test myself. Apparently I'm as confused as ever:
It certainly appears to me that this tree has two levels - a first level with one limb and a second with 10 limbs - and that I should be able to index it with {0;0} and retrieve a tree with one item in it - the list {0}. The panel data seems to confirm this with indices of {0;0;0}, etc. so I put this path in with quite a bit of confidence that it would work and...bust. The error reads "Path {0;0} does not exist within this tree". Huh? Again, I'm just so confused.…
Added by Darrell Plank at 12:17am on January 20, 2015
ers and researchers, programmers and artists, professionals and academics who come together for 4 days of intense collaboration, development, and design.
The sg2012 Workshop will be organised around Clusters. Clusters are hubs of expertise. They comprise of people, knowledge, tools, materials and machines. The Clusters provide a focus for workshop participants working together within a common framework.
Clusters provide a forum for the exchange of ideas, processes and techniques and act as a catalyst for design resolution. The Workshop is made up of ten Clusters that respond in diverse ways to the sg2012 Challenge Material Intensities.
Applicants to the sg2012 Workshop will select their preferred cluster from the following:
Beyond Mechanics
Micro Synergetics
Composite Territories
Ceramics 2.0
Material Conflicts
Transgranular Perspiration
Reactive Acoustic Environments
Form Follows Flow
Bioresponsive Building Envelopes
Gridshell Digital Tectonics
More information about the Workshop and Clusters can be found here:
http://smartgeometry.org/index.php?option=com_content&view=article&id=116&Itemid=131
The application process will close on January 15th, 2012.
Full Fee $1500
Reduced Fee $750
Scholarship Fee $350
Fees include attendance to both the workshop and conference from March 19th-24th.
Reduced Fee and Scholarships are available only for Academics, Students and Young Practitioners, and are awarded during a competitive peer review process.
sg2012 takes place from 19-24 March 2012 at EMPAC (http://empac.rpi.edu/) and is hosted by Rensselaer Polytechnic Institute in Troy, upstate New York USA. The Workshop and Conference will be a gathering of the global community of innovators and pioneers in the fields of architecture, design and engineering.
The event will be in two parts: a four day Workshop 19-22 March, and a public conference beginning with Talkshop 23 March, followed by a Symposium 24 March. The event follows the format of the highly successful preceding events sg2010 Barcelona and sg2011 Copenhagen.
sg2012 Challenge Material Intensities
Simulation, Energy, Environment
Imagine the design space of architecture was no longer at the scale of rooms, walls and atria, but that of cells, grains and vapour droplets. Rather than the flow of people, services, or construction schedules, the focus becomes the flow of light, vapour, molecular vibrations and growth schedules: design from the inside out.
The sg2012 challenge, Material Intensities, is intended to dissolve our notion of the built environment as inert constructions enclosing physically sealed spaces. Spaces and boundaries are abundant with vibration, fluctuating intensities, shifting gradients and flows. The materials that define them are in a continual state of becoming: a dance of energy and information. Material potential is defined by multiple properties: acoustical, chemical, electrical, environmental, magnetic, manufacturing, mechanical, optical, radiological, sensorial, and thermal. The challenge for sg2012 Material Intensities is to consider material economy when creating environments, micro-climates and contexts congenial for social interaction, activities and organisation. This challenge calls for design innovation and dialogue between disciplines and responsibilities. sg2010 Working Prototypes strove to emancipate digital design from the hard drive by moving from the virtual to the actual in wrestling with the tangible world of physical fabrication. sg2011 Building the Invisible focused on informing digital design with real world data. sg2012 Material Intensities strives to energise our digital prototypes and infuse them with material behaviour. They have the potential to become rich simulations informed by the material dynamics, chemical composition, energy flows, force fields and environmental conditions that feed back into the design process.
More information can be found at http://www.smartgeometry.org
Follow us on Twitter at http://twitter.com/smartgeometry…
Added by Shane Burger at 12:29pm on December 13, 2011