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
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te some cut sheets, but not to optmize material, rather define some cut lines. Everything that I am cutting is made of planar wood elements, but there are very specific geometries (mostly straight lines) and I have to put tolerances and radiasas at the corners in order to cut on the cnc mill. Spending time to figure out how to automate is necessary, but I am stuck!
One thing the definition is doing is taking my brep modeled components in rhino and makking them into 2d close curves and laying them side by side. It works...not ideal as its not layed out in a sheet, but that is not the most important part.
Another particular problem is that you will see some notches in the curves, which other pieces will slip into, so different slots need different specific offsets (making them larger) as a toelrance to allow for material play. This I don't even know how to set up so maybe it will just have to wait.
THE MAIN QUESTION, and super important would be, LIFESAVER:
At all 'inward' corners...which I think will always mean concave corners (most are 90 degrees, but are within to sides, instead of a corner sticking out). I'm sure its obviousy, but the reason being the outward corners a circular dril bit can cut, but inward ones need an arc profile extended beyond where the corner of the other piece will fit into. The drill bit i am using is 6mm, so 6mm diamters arcs is what i'm working with.
I have managed to put such an arc at every vertices of each cut piece. The problem being some stick outward isntead of cutting into the piece. So each one needs to be orieneted correctly. Ideally they would also only draw into inward corners, but I can always delete them out. I think maybe I am missing a more logical mathematical way of defining?
For these geometries it is not very important which side the half circle arc in on in the inward corners, but I also have some geometries that I will have to control where the circles face according to the rest of the cut piece.
The cutouts in the middle of the pieces that are curves do not need such corners obviously.
The picture is an example drawn
I hope this isn't too specific and long. in general though automating fabrication, and controling pracitcal math and orientation problems like this is itnersting to me!
THANKS…
perienced with grasshopper, but so far I've managed to combine the following:
Giulio Piacentino's "Catenary arch from height" script
Pirouz Nourian's "Mobius" script (Obtained from a friend)
End Result:
Here's where I'm stuck: I want the mobius twist to revolve around the midpoint of the arch, but the script uses the input values to determine the endpoints, resulting in a weird sinuous shape when viewed from above. Also, the secondary end points (generated by the mobius script, determining the width of the surface) are generated by default along the z axis, resulting in an arch that only touches the "ground" at two points. I attempted to work around this issue by trying to force the zHeight parameter to correspond with the y axis (thus rotating the arch 90 degrees so it would lay "flat"), but the script interprets the third point as a value and not as an actual point to bisect. I thought this might be an issue with the C# component that I obtained from Giulio Piacentino's script, so I attempted to tinker around with the source code. Unfortunately, I'm not fluent in C# so I only managed to mess everything up (I've since recovered the code from the cache). Anybody got some ideas? -BC …
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
thing that MicroStation does (or doesn't). The eternal debate between us is that they focus to the so called BIM aspect of things (and obviously on interoperability matters - that said IFC2*4 is" implemented" in certain Bentley verticals like BA and others) whilst I'm after assembly/component puzzles (and on that matter ... MS ...hmm... to put it politely is not exactly CATIA and/or NX, he he).
On the other hand this paranoid obsession with Level/Layer driven CAD (I hate it) defines a red thick line between CAD and MCAD - because the most intelligent importer can't emulate the way that Siemens NX/CATIA classifies objects - and without control power means nothing.
On the other hand Microstation V9 (...soon) has interesting scripting capabilities (think Modo rather Generative Components) ... meaning that Grasshopper could work there in a rather nice way. I think that I must talk for that to Ray (he recently ditched the ancient legacy MS render engine in favor for the Luxology/Nexus engine). Ray still is negative to buy Act3D mind (hope that you know the mother of visual scripting - the Quest3D VR thing).
On the other hand - within the broad AEC aspect - things these days are different (especially in fast developing countries the likes of UAE, Saudi Arabia, certain ex USSR "democracies" etc etc). Studies are outsourced even at Preliminary Design stage to various sub-contractors (they undertake the Study completion per discipline as well). This means that N separate groups doing M aspects of the whole ... meaning entropy^(N*M) - that's chaos in plain English.
With this in mind I'm quite (a lot) skeptical about the practical meaning of the whole exchange thing in AEC - at least with regard the countries mentioned (not to mention that several portions of a modern AEC thing are made via MCAD apps - chaos^chaos.
I'll back with more focused issues on that matter.
But the big question is: Grasshopper of Generative Components? Well...let's talk serious SS bikes instead: think a Ducati 1198 and a BMW S1000RR (I have them both): which is "best"? The thing is that not always the best bunny is the fasted bunny and not always the fasted bunny is the best bunny.
Cheers,
Peter
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ty to work in a new and exciting space, where design, art, technology and fashion meet.
If you guys are looking for a full- or part-time job, or know an expert who is - we're happy to with meet him/her. We're located in the Lower East Side, New York.
What the person will be doing:
- Provide technical vision for product and infrastructure features
- Work with Marketing/Product Management to enhance the user experience
- Develop (with our team) our e-commerce customization platform
- Manage our real time 3D modeling platform
- Mentor 3D modelers and developers, define and document development methods, and share best practices
- Review and recommend improvements to product architecture
What we require:
- BA/BS/ BARCH degree OR CS/EE/Engineering degree preferred
- EXTENSIVE 3d modeling, rhino and grasshopper experience
- Experience building online computer games
- Experience creating natural and fractal patterns and forms in 3d
- UV Texture Mapping bit mapping (texture mapping)
- Experience managing a development team in projects with tight SCHEDULES
- Architecture, programing, scripting, Media or Fashion industry experience preferred
- Experience implementing web interfaces using XHTML, CSS, Javascript, and AJAX
- Experience in recommendation engines and algorithms
- Interest in working in an early stage fast-paced environment…
ting at multiple geometries in the same location. I simply sorted the list of values and used the Delete Consecutive component. This potentially rearranges the order of values but I don't think that matters in your case. I also threw in an Int component which actually seems to make a difference (try sidestepping it and you will see!).
2-I flattened the output of the mesh component before sending it to union. This ensures that the original mesh is booleaned once with all the components rather than individually with each of the 86 components.
Is this what the result should look like?
One suggestion for future postings: when referencing geometry in rhino, it often helps if you attach your rhino file as well so people don't have to guess where you are starting from.
If you have further questions, just ask ;-)
cbass…