e a fundamental failure on my part. On the other hand, Grasshopper isn't supposed to be on a par with most other 3D programs. It is emphatically not meant for manual/direct modelling. If you would normally tackle a problem by drawing geometry by hand, Grasshopper is not (and should never be advertised as) a good alternative.
I get that. That’s why that 3D shape I’m trying to apply the voronoi to was done in NX. I do wonder where the GUI metaphor GH uses comes from. It reminds me of LabVIEW.
"What in other programs is a dialog box, is 8 or 10 components strung together in grasshopper. The wisdom for this I often hear among the grasshopper community is that this allows for parametric design."
Grasshopper ships with about 1000 components (rounded to the nearest power of ten). I'm adding more all the time, either because new functionality has been exposed in the Rhino SDK or because a certain component makes a lot of sense to a lot of people. Adding pre-canned components that do the same as '8 or 10 components strung together' for the heck of it will balloon the total number of components everyone has to deal with. If you find yourself using the same 8 to 10 components together all the time, then please mention it on this forum. A lot of the currently existing components have been added because someone asked for it.
It’s not the primary components that catalyzed this thought but rather the secondary components. I was toying with a component today (twist from jackalope) that made use of three toggle components. The things they controlled are checkboxes in other apps.
Take a look at this jpg. Ignore differences; I did 'em quickly. GH required 19 components to do what SW did with 4 commands. Note the difference in screen real estate.
As an aside, I really hate SolidWorks (SW). But going forward, I’ll use it as an example because it’s what most people are familiar with.
"[...] has a far cleaner and more intuitive interface. So does SolidWorks, Inventor, CATIA, NX, and a bunch of others."
Again, GH was not designed to be an alternative to these sort of modellers. I don't like referring to GH as 'parameteric' as that term has been co-opted by relational modellers. I prefer to use 'algorithmic' instead. The idea behind parameteric seems to be that one models by hand, but every click exists within a context, and when the context changes the software figures out where to move the click to. The idea behind algorithmic is that you don't model by hand.
I agree, and disagree. I believe parametric applies equally to GH AND SW, NX, and so forth, while algorithmic is unique to GH (and GC and Dynamo I think). Thus I understand why you prefer the term. I too tend to not like referring to GH as a parametric modeler for the same reason.
But I think it oversimplifies it to say parametric modelers move the clicks. SW tracks clicks the same way GH does; GH holds that information in geometry components while SW holds it in a feature in the feature tree. In both GH and SW edits to the base geometry will drive a recalculation, but more commonly, it’s an edit to input data, beit equations or just plain numbers, that drive a recalculation.
I understand the difference in these programs. What brought me to GH is that it can create a visual dialog that standard modelers can’t. But as I've grown more comfortable with it I’ve come to realize that the GUI of GH and the GUI of other parametric modelers, while looking completely different, are surprisingly interchangeable. Do not misconstrue that I’m suggesting that GH should replace it’s GUI with SW’s. I’m not. I refrain from suggesting anything specific. I only suggest that you allow yourself to think radically.
This is not to say there is no value in the parametric approach. Obviously it is a winning strategy and many people love to use it. We have considered adding some features to GH that would make manual modelling less of a chore and we would still very much like to do so. However this is such a large chunk of work that we have to be very careful about investing the time. Before I start down this road I want to make sure that the choice I'm making is not 'lame-ass algorithmic modeller with some lame-ass parametrics tacked on' vs. 'kick-ass algorithmic modeller with no parametrics tacked on'.
Given a choice, I'd pick kick-ass algorithmic modeller with no parametrics tacked on.
2. Visual Programming.
I'm not exactly sure I understand your grievance here, but I suspect I agree. The visual part is front and centre at the moment and it should remain there. However we need to improve upon it and at the same time give programmers more tools to achieve what they want.
I'll admit, this is a bit tough to explain. As I've re-read my own comment, I think it was partly a precursor to the context sensitivity point and touched upon other stated points.
This now touches upon my own ignorance about GH’s target market. Are you moving toward a highly specialized tool for programmers and/or mathematicians, or is the intent to create a tool that most designers can master? If it’s the former, rock on. You’re doing great. If it’s the latter, I’m one of the more technically sophisticated designers I know and I’m lost most of the time when using GH.
GH allows the same freedom as a command line editor. You can do whatever you like, and it’ll work or not. And you won’t know why it works or doesn't until you start becoming a bit of an expert and can actually decipher the gibberish in a panel component. I often feel GH has the ease of use of DOS with a badass video card in front.
Please indulge my bit of storytelling. Early 3D modelers, CATIA, Unigraphics, and Pro-Engineer, were unbelievably difficult to use. Yet no one ever complained. The pain of entry was immense. But once you made it past the pain threshold, the salary you could command was very well worth it. And the fewer the people who knew how to use it, the more money you could demand. So in a sense, their lack of usability was a desirable feature among those who’d figured it out.
Then SolidWorks came along. It could only do a fraction of what the others did, but it was a fraction of the cost, it did most of what you needed, and anyone could figure it out. There was even a manual on how to use it. (Craziness!) Within a few short years, the big three all had to change their names (V5, NX, and Wildfire (now Creo)) and change the way they do things. All are now significantly easier to use.
I can tell that the amount of development time that’s gone into GH is immense and I believe the functionality is genius. I also believe it’s ease of use could be greatly improved.
Having re-read my original comments, I think it sounded a bit snotty. For that I apologize.
3. Context sensitivity.
"There is no reason a program in 2014 should allow me to make decisions that will not work. For example, if a component input is in all cases incompatible with another component's output, I shouldn't be able to connect them."
Unfortunately it's not as simple as that. Whether or not a conversion between two data types makes sense is often dependent on the actual values. If you plug a list of curves into a Line component, none of them may be convertible. Should I therefore not allow this connection to be made? What if there is a single curve that could be converted to a line? What if you want to make the connection now, but only later plan to add some convertible curves to the data? What you made the connection back when it was valid, but now it's no longer valid, wouldn't it be weird if there was a connection you couldn't make again?
I've started work on GH2 and one of the first things I'm writing now is the new data-conversion logic. The goal [...] is to not just try and convert type A into type B, but include information about what sort of conversion was needed (straightforward, exotic, far-fetched. etc.) and information regarding why that type was assigned.
You are right that under some conditions, we can be sure that a conversion will always fail. For example connecting a Boolean output with a Curve input. But even there my preferred solution is to tell people why that doesn't make sense rather than not allowing it in the first place.
You bring up both interesting points and limits to my understanding of coding. I’ve reached the point in my learning of GH where I’m just getting into figuring out the sets tab (and so far I’m not doing too well). I often find myself wondering “Is all of this manual conditioning of the data really necessary? Doesn’t most software perform this kind of stuff invisibly?” I’d love to be right and see it go away, but I could easily be wrong. I’ve been wrong before.
5. Components.
"Give components a little “+” or a drawer on the bottom or something that by clicking, opens the component into something akin to a dialog box. This should give access to all of the variables in the component. I shouldn't have to r-click on each thing on a component to do all of the settings."
I was thinking of just zooming in on a component would eventually provide easier ways to access settings and data.
I kinda like this. It’s a continuation of what you’re currently doing with things like the panel component.
"Could some of these items disappear if they are contextually inappropriate or gray out if they're unlikely?"
It's almost impossible for me to know whether these things are 'unlikely' in any given situation. There are probably some cases where a suggestion along the lines of "Hey, this component is about to run 40,524 times. It seems like it would make sense to Graft the 'P' input." would be useful.
6. Integration.
"Why isn't it just live geometry?"
This is an unfortunate side-effect of the way the Rhino SDK was designed. Pumping all my geometry through the Rhino document would severely impact performance and memory usage. It also complicates the matter to an almost impossible degree as any command and plugin running in Rhino now has access to 'my' geometry.
"Maybe add more Rhino functionality to GH. GH has no 3D offset."
That's the plan moving forward. A lot of algorithms in Rhino (Make2D, FilletEdge, Shelling, BlendSrf, the list goes on) are not available as part of the public SDK. The Rhino development team is going to try and rectify this for Rhino6 and beyond. As soon as these functions become available I'll start adding them to GH (provided they make sense of course).
On the whole I agree that integration needs a lot of work, and it's work that has to happen on both sides of the isle.
You work for McNeel yet you seem to speak of them as a separate entity. Is this to say that there are technical reasons GH can only access things through the Rhino SDK? I’d think you would have complete access to all Rhino API’s. I hope it’s not a fiefdom issue, but it happens.
7. Documentation.
Absolutely. Development for GH1 has slowed because I'm now working on GH2. We decided that GH1 is 'feature complete', basically to avoid feature creep. GH2 is a ground-up rewrite so it will take a long time until something is ready for testing. During this time, minor additions and of course bug fixes will be available for GH1, but on a much lower frequency.
Documentation is woefully inadequate at present. The primer is being updated (and the new version looks great), but for GH2 we're planning a completely new help system. People have been hired to provide the content. With a bit of luck and a lot of work this will be one of the main selling points of GH2.
It begs the question that I have to ask. When is GH1.0 scheduled to launch? And if you need another person to proofread the current draft of new primer.
patrick@girgen.com
I can’t believe wikipedia has an entry for feature creep. And I can’t believe you included it. It made me giggle. Thanks.
8. 2D-ness.
"I know you'll disagree completely, but I'm sticking to this. How else could an omission like offsetsurf happen?"
I don't fully disagree. A lot of geometry is either flat or happens inside surfaces. The reason there's no shelling (I'm assuming that's what you meant, there are two Offset Surface components in GH) is because (a) it's a very new feature in Rhino and doesn't work too well yet and (b) as a result of that isn't available to plugins.
I believe it’s been helpful for me to have figured this out. I recently completed a GH course at a local Community College and have done a bunch of online tutorials. The first real project I decided to tackle has turned out to be one of the more difficult things to try. It’s the source of the questions I posted. (Thanks for pointing out that they were posted in the wrong spot. I re-posted to the discussions board.)
I just can't seem to figure out how to turn the voronoi into legitimate geometry. I've seen this exact question posted a few times, but it’s never been successfully answered. What I'm showing here is far more angular than I’m hoping for. The mesh is too fine for weaverbird to have much of an effect. And I haven't cracked re-meshing. Btw, in product design, meshes are to be avoided like the plague. Embracing them remains difficult.
As for offsetsurf, in Rhino, if you do an offsetsurf to a solid body, it executes it on all sides creating another neatly trimmed body thats either larger or smaller than the original. This is how every other app I know of works. GH’s offsetsurf creates a bunch of unjoined faces spaced away from the original brep. A common technique for 3D voronois (Yes, I hit the voronoi overuse easter egg) is to find the center of each cell and scale them by this center. If you think about it, this creates a different distance from the face of the scaled cell to the face of the original cell for every face. As I've mentioned, this project is giving me serious headaches.
Don't get me wrong, I appreciate the feedback, I really do, but I want to be honest and open about my own plans and where they might conflict with your wishes. Grasshopper is being used far beyond the boundaries of what we expected and it's clear that there are major shortcomings that must be addressed before too long. We didn't get it right with the first version, I don't expect we'll get it completely right with the second version but if we can improve upon the -say- five biggest drawbacks (performance, documentation, organisation, plugin management and no mac version) I'll be a happy puppy.
--
David Rutten
Thank you for taking the time to reply David. Often we feel that posting such things is send it into the empty ether. I’m very glad that this was not the case.
And thank you for all of the work you've put into GH. If you found any of my input overly harsh or ill-mannered, I apologise. It was not my intent. I'm generally not the ranting sort. If I hadn't intended to provide possibly useful input, I wouldn't have written.
Cheers
Patrick Girgen
Ps. Any pointers on how to get a bit further on the above project would be greatly appreciated.
…
e is that this code is needlessly complex and, for two reasons, just plain wrong:
Did you notice that both 'Item (List Item)' components return the same value? That's due to an off-by-one error for the second one; it should be 'Lng - 1'. With 'Wrap=True', you were getting element 0 instead of element 'Lng - 1' (list elements are zero-based).
'Graft' on the 'Dom' inputs is pointless. You could do it this way:
Or even easier, as I suggested yesterday, use the 'Bounds (Bnd)' component to get the same result - that's what it's for!
I quit looking at that point, in large part because I didn't have your surface. Now that you have posted the Rhino file, I'm digging a little deeper and see other issues. I can't over emphasize how incredibly important it is to post your whole model!!! So much time is wasted otherwise.
I will not follow you to the duplicate thread you created and hope you will delete it.
Why are you using two attractor points? I chose only one of them.
I went through the rest of your code and fixed things as I saw fit to get this:
As you can see, the remaining problem is due to your trimmed sphere surface. The points and resulting 'Loft' bits that are not on the trimmed surface need to be culled. Quit simple really, if you look at the 'D (Distance)' output of 'Srf CP'. Like this (TRY1_2017Mar18b.gh):
Did you mean to leave the holes? If not, you can skip 'Edges', move the scaled surfaces, then 'Loft' and 'Join' them so the pyramids become 'Closed Breps' (TRY1_2017Mar18c.gh):
All three versions (attached) have your surface and points internalized so no need for Rhino file. See how easy that is when the whole model is available?…
Added by Joseph Oster at 11:52am on March 18, 2017
s o alguna de sus partes con la máquina de control numérico de ControlMAD. La finalidad es entrar en contacto con las herramientas disponibles ( control numérico, corte por láser, brazo robótico, scanner 3D..) para construir formas y superficies de geometría compleja a partir del 3D del ordenador.
El curso se acompaña de visitas para conocer de primera mano el trabajo con estas herramientas digitales.Duración: 48 horas:Clases de 3D: Modelado con RHINO (16 horas) + GRASSHOPPER (8 horas) + Vray (4 horas)Proyecto personal tutorado y fabricado en su totalidad o en la parte más significativa con la máquina de control numéricoVisitas programadas:Taller de maquetas. Maquetas de arquitectura para estudios como Zaha Hadid o Moneo. Trabajan con láser y control numérico.Fundición Capa: han realizado esculturas para Dalí, Oteiza o Manolo Valdés entre otros. Trabajan con scanner 3D y brazo robótico.Pasarela sobre el Manzanares, de D. Perrault.…
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…
is also takes place in own system. However, this action can be also carried out successfully by a foreign reference, if this considers the focused system as own. Hence, these two criteria are considered in my reflexions, to make your criticism handier for me.
First the question must be put up, how is it in your case? Of friendly manner you answer this question perpetually with the statement that you are not a partial of the system of the architecture.
Furthermore the question would be appropriate, whether an external reference (eg CAD) determined architecture. This can be answered with no, because determining and influencing are different things.
Because you stress now your criticism as a foreign criticism, within the architecture the assuption must be put up, that this criticism is not unusual new on the one hand (because this condition were also in other times like that, and presumably also always so remain) and further more a lack of goodwill in your criticism comes to light, which perhaps distinguishes an external reference.
Based on your critique, it would be also desirable in the system of the architecture if the academic rules become satisfyingly followed, even if this is no guarantor for good academic works. Nevertheless, there is an aspect which at least tolerates the evident lack in the Interdiziplinarität of the architecture. This is the classical and still valid determination of the architecture, presumably regulates not only the actions of the architects, but also those who want to become it.
Many who stand in your criticism (the students, as well as the teachers, ... ), live in the awareness that architecture is a profession that combines as many areas around the topic of Building, and the architect is even only one dilettante among the external specialists. In this determination dilettantism is revalued rather positively, because this state the architects enables to assess the facets of a complicated building project better and to form thereby the whole result positively. To be a good architect, you should have circumspect specialists around yourself. And exactly this knows the system of the architecture, because "THE ARCHITECT" helps himself with the logic of other systems (to repair on the one hand his own deficits), and to create an artificial complexity, which ultimately aims to be the complexity of human beeing.
Here "THE ARCHITECTS" becomes a quality-spoken, which currently seems the external reference (CAD, BIM) would like to take claim for themselves.
........
If would not thought about it, this might be helpful:http://www.amazon.com/The-Alphabet-Algorithm-Writing-Architecture/dp/0262515806/ref=sr_1_1?ie=UTF8&qid=1376920450&sr=8-1&keywords=mario+carpo"Finally, I’d like to restate my criticisms in general terms. If we are serious about moving architecture and urbanism away from purely artistic considerations and into a more rational arena, there has never been a better time than now. All of us have access to immense computational power which can be applied to problems that have been —until quite recently— intractable. But of course the garbage-in-garbage-out adage holds true; computation can be used to generate large amounts of complexity, but complexity does not equal worth. The only time when it makes sense to invoke computation in the design process is when there is some relevant data that needs to be computed" (David Rutton)I want to make it short, and just ask a few questions, and hope that the following questions are relevant also for you, and not be considered outside your system. i think that the weighting to such questions seem to be more valuable, not for the architects.1. What is wrong from a pure artistic intention?2. What is any sense in purely architectural discourse?3. strictly looked, can be determined sense generally in a purely architectural discourse?4. What is purely architectural discourse?5. What is Funktionalismus or Rationalismus without philosophical support? 6. Would not be the pure functional fulfilment empty ? 7. Would be not a critical position on the promise of purely rational algorithms applied?…
of pitch forwards and backwards2. What effect do the following have on the system... a) Angle of Attack (AOA) of the front wing b) AOA of the rear wing c) Position of the mast along the fuselage. d) Position of rider above the mast (distribution of weight between front and rear feet amd position of the mast between the feet).So, in essence I want to model a 2 dimensional system as follows...I would like to incorporate a coefficient of lift versus AOA for the front and rear wings.Data for this can be found in text file format for example here for the Eppler 817 airfoil that I want to use... EPPLER817 DATAI might need more info than this though???Assume constant velocity???Ultimately, the lift generated by the hydrofoil will equal the weight of the rider otherwise you would sink or jump forever upwards but the hydrofoil can generate more lift or less lift than the rider depending on its angle of attack. I could assume the wing can generate -1.0x to 1.5x the weight of the rider in lift?The rear wing is usually approx 1/3 the size of the front wing. So perhaps assume 1/3 of the lift of the front wing although I will probably use a different airfoil section which will have different lift characteristics.Assume the rider can shift weight forwards and backwards between front foot and rear foot to keep the foil level, but perhaps include a time lag or some means of indicating how stable the system is.Ignore the water surface and assume the wings remain submerged.I want to assess the difference between having an AOA on the front wing and no AOA on the rear wing versus no AOA on the front but a AOA that creates a downforce on the rear wing (Which is how they are normally configured I think). I believe the rear wing is alwasy trying to pitch the front wing upwards creating a greater AOA and hence more lift. The rider has to keep pressure on their front foot to stop the front wing stalling and control the lift to be equal to their weight.My aim is to understand what parameters to use for front wing AOA, rear wing AOA and mast position to create a hydrofoil that is stable but not so stable that it takes a lot of effort to pitch it forwards and backwards. So I'm not looking for the most stable configuration, I'm looking to avoid something that is really unstable or requires (for example) the rider to put 100% of weight on one foot!Is it possible to create a meaningful simulation of this with Kangaroo 1 or 2? I made a start... Not sure I've approached it in the right way and haven't attempted to add the coefficient of lift vs AOA feedback.A video of kite hydrofoiling...
More info for those still reading...Kite hydrofoils come in many shapes and sizes... there are high aspect ration wings for racing, low aspect wings for beginners / low speed. There seem to be many configurations of mast position, feet position over the mast, length of fuselage, size of front wing to rear wing etc etc. I'm planning on CNC machining the front wing, fuselage and rear wing in one piece made up from bamboo. Then applying glass fibre or carbon fibre. I already have an aluminium mast and will make a board.…
Added by martyn hogg at 1:52pm on November 14, 2016
to incorporating math and geometry in computational design education, Paneling Tools
Marlo Ransdell, PhD Creative Director, at FSU , Digital Fabrication in Design Research and Education
Andy Payne, LIFT architects | Harvard GSD | FireFly
Jay H Song, Chair, Jewelry School of Design, Jewelry as Personal Expression, Extra+Ordinary@Jewelry.com
Pei- Jung (P.J.) Chen, Professor of Jewelry, SCAD
Gustavo Fontana, designer/co-founder nimbistand, Diseñar, desarrollar y comercializar productos por tu cuenta.
Joe Anand, CEO MecSoft Corporation, RhinoCAM
Julian Ossa, Chair, Industrial Design Director, Diseño – Una opción de vida a todo vapor!, UPB
Minche Mena, SHINE Architecture, Principal
J. Alstan Jakubiec, Daylighting and Environmental Performance in Architectural Design Solemma, LLC
Carlos Garnier R&D Director / Jaime Cadena – General Director, Plug Design, www.plugdesign.com.mx
Mario Nakov, www.chaosgroup.com [ V-Ray ]
Andres Gonzalez, RhinoFabStudio
Workshops:
o) Paneling Tools
o) RhinoCAM
o) Rhinology in Design, for Jewelry
o) Footwear
o) V-Ray: Jewelry Design
o) V-Ray: Architects and Industrial Designers
o) FireFly
o) J. Alstan Jakubiec, DIVA
The cost for each workshop or the Lectures is 95.0 US$
To register:
WORK-SHOPS April 2 - RHINO DAY
WORK-SHOPS April 3 - RHINO DAY
REGISTRATION RHINO DAY
NOTE: All students and faculty members that register to this event, will receive a Rhino 5 Educational License at the event.
…
the platform. Crv
Algorithm:
Bounding box on a mesh for extraction of Z dimensions.
Zmin
Zmax
Filtering curve (Closed and Planar Curve), extraction of the Z position of the curve
ZCurve
Crv(Base)
Plan(Base)
We deduce the difference between the position of the curve and the position of the mesh.
DeltaZ
From a slider (0 to 1) we remap value of a slider to the Delta Z. We get the height of the curve test.
ZCurve*
*(At position 0, the curve at the lower Z mesh. At position 1 is the highest of the Z mesh)
Move of the curve on Z.
Crv (Base)
Divide curve on a vertical plane.(RCE : Plane on Curve)
For a closed curve t parameter is 0. For a closed polyline t parameter is 0 and 1.
Cut & Fill Profile(RCE :Cut & Fill Profile)
We take as a parameter Cutt & Fill: Delta Z.
3D Modeling Cutt & Fill platform.
Bounding box of a main project.(RCE :Bounding box)
Creating base of a mesh in main project.
Boolean operation to the cut & fill platform.
Volume and display.
Optimization with Galapagos .
Galapagos Editor.
Verification
The base curve may be a polyigne or a NURBS curve to avoid a problem of computing a set of component may be added to the definition .
Example available in bottom of this post...
[EXEMPLE_Français] Optimisation Plateforme Déblais & Remblais avec Galapagos.
But:
Dans cet exemple nous allons voir comment utiliser RCE(RhinoCivil Engineering) dans une étude d'optimisation de déblais et de remblais sur une plateforme.
Données:
Maillage représentant le terrain. Mesh (A)
Courbe représentant la plateforme. Crv
Algorithme :
Boite de contour du maillage du terrain pour extraction des dimensions en Z de la boite.
Zmin
Zmax
Filtrage de la courbe (courbe plane et fermée), extraction de la position en Z de la courbe.
ZCurve
Crv(Base)
Plan(Base)
Nous en déduisons la différence entre la position de la courbe et la position du maillage.
DeltaZ
A partir d’un slider (0 à 1), nous remappons la valeur du slider d’un domaine 0 à 1 vers la domaine correspondant au Delta Z. Nous obtenons l’altitude de la courbe à tester.
ZCurve*
*(A la position 0 du slider la courbe est au plus bas du maillage du terrain et à la position 1 la courbe est au plus haut du maillage du terrain. L’optimum du déblais remblais doit probablement se trouver entre ces deux valeurs).
Déplacement de la courbe en Z.
Crv (Base)
Division de la courbe par un plan vertical.(RCE : Plan sur Courbe)
Pour une courbe fermée le paramètre t est 0, pour une polyligne fermée le paramètre t est 0 et 1.
Dessin de profils déblais et remblais.(RCE :Profil déblais & remblais simple)
Nous prenons comme paramètre de rattrapage en déblais et remblais Delta Z.
Modélisation de la plateforme en déblais et en remblais.
Création de la boite de contour du projet.(RCE :Boîte)
Création du socle du Terrain dans la zone du projet.
Opération booléenne pour la plateforme en déblais et en remblais.
Calcul de volume et affichage.
Optimisation avec Galapagos.
Galapagos Editeur.
Vérification
La courbe de base peut être une polyigne ou une courbe NURBS, pour éviter un problème de calcul un ensemble de composant peut être ajouté à la définition.
…
lly it should not make much of a difference - random number generation is not affected, mutation also is not. crossover is a bit more tricky, I use Simulated Binary Crossover (SBX-20) which was introduced already in 1194:
Deb K., Agrawal R. B.: Simulated Binary Crossover for Continuous Search Space, inIITK/ME/SMD-94027, Convenor, Technical Reports, Indian Institue of Technology, Kanpur, India,November 1994
Abst ract. The success of binary-coded gene t ic algorithms (GA s) inproblems having discrete sear ch sp ace largely depends on the codingused to represent the prob lem variables and on the crossover ope ratorthat propagates buildin g blocks from pare nt strings to childrenst rings . In solving optimization problems having continuous searchspace, binary-co ded GAs discr et ize the search space by using a codingof the problem var iables in binary st rings. However , t he coding of realvaluedvari ables in finit e-length st rings causes a number of difficulties:inability to achieve arbit rary pr ecision in the obtained solution , fixedmapping of problem var iab les, inh eren t Hamming cliff problem associatedwit h binary coding, and processing of Holland 's schemata incont inuous search space. Although a number of real-coded GAs aredevelop ed to solve optimization problems having a cont inuous searchspace, the search powers of these crossover operators are not adequate .In t his paper , t he search power of a crossover operator is defined int erms of the probability of creating an arbitrary child solut ion froma given pair of parent solutions . Motivated by t he success of binarycodedGAs in discret e search space problems , we develop a real-codedcrossover (which we call the simulated binar y crossover , or SBX) operatorwhose search power is similar to that of the single-point crossoverused in binary-coded GAs . Simulation results on a number of realvaluedt est problems of varying difficulty and dimensionality suggestt hat the real-cod ed GAs with t he SBX operator ar e ab le to perform asgood or bet t er than binary-cod ed GAs wit h t he single-po int crossover.SBX is found to be particularly useful in problems having mult ip le optimalsolutions with a narrow global basin an d in prob lems where thelower and upper bo unds of the global optimum are not known a priori.Further , a simulation on a two-var iable blocked function showsthat the real-coded GA with SBX work s as suggested by Goldberg
and in most cases t he performance of real-coded GA with SBX is similarto that of binary GAs with a single-point crossover. Based onth ese encouraging results, this paper suggests a number of extensionsto the present study.
7. ConclusionsIn this paper, a real-coded crossover operator has been develop ed bas ed ont he search characte rist ics of a single-point crossover used in binary -codedGAs. In ord er to define the search power of a crossover operator, a spreadfactor has been introduced as the ratio of the absolute differences of thechildren points to that of the parent points. Thereaft er , the probabilityof creat ing a child point for two given parent points has been derived forthe single-point crossover. Motivat ed by the success of binary-coded GAsin problems wit h discrete sear ch space, a simul ated bin ary crossover (SBX)operator has been develop ed to solve problems having cont inuous searchspace. The SBX operator has search power similar to that of the single-po intcrossover.On a number of t est fun ctions, including De Jong's five te st fun ct ions, ithas been found that real-coded GAs with the SBX operator can overcome anumb er of difficult ies inherent with binary-coded GAs in solving cont inuoussearch space problems-Hamming cliff problem, arbitrary pr ecision problem,and fixed mapped coding problem. In the comparison of real-coded GAs wit ha SBX operator and binary-coded GAs with a single-point crossover ope rat or ,it has been observed that the performance of the former is better than thelatt er on continuous functions and the performance of the former is similarto the lat ter in solving discret e and difficult functions. In comparison withanother real-coded crossover operator (i.e. , BLX-0 .5) suggested elsewhere ,SBX performs better in difficult test functions. It has also been observedthat SBX is particularly useful in problems where the bounds of the optimum
point is not known a priori and wher e there are multi ple optima, of whichone is global.Real-coded GAs wit h t he SBX op erator have also been tried in solvinga two-variab le blocked function (the concept of blocked fun ctions was introducedin [10]). Blocked fun ct ions are difficult for real-coded GAs , becauselocal optimal points block t he progress of search to continue towards t heglobal optimal point . The simulat ion results on t he two-var iable blockedfunction have shown that in most occasions , the sea rch proceeds the way aspr edicted in [10]. Most importantly, it has been observed that the real-codedGAs wit h SBX work similar to that of t he binary-coded GAs wit h single-pointcrossover in overcoming t he barrier of the local peaks and converging to t heglobal bas in. However , it is premature to conclude whether real-coded GAswit h SBX op erator can overcome t he local barriers in higher-dimensionalblocked fun ct ions.These results are encour aging and suggest avenues for further research.Because the SBX ope rat or uses a probability distribut ion for choosing a childpo int , the real-coded GAs wit h SBX are one st ep ahead of the binary-codedGAs in te rms of ach ieving a convergence proof for GAs. With a direct probabilist ic relationship between children and parent points used in t his paper,cues from t he clas sical stochast ic optimization methods can be borrowed toachieve a convergence proof of GAs , or a much closer tie between the classicaloptimization methods and GAs is on t he horizon.
In short, according to the authors my SBX operator using real gene values is as good as older ones specially designed for discrete searches, and better in continuous searches. SBX as far as i know meanwhile is a standard general crossover operator.
But:
- there might be better ones out there i just havent seen yet. please tell me.
- besides tournament selection and mutation, crossover is just one part of the breeding pipeline. also there is the elite management for MOEA which is AT LEAST as important as the breeding itself.
- depending on the problem, there are almost always better specific ways of how to code the mutation and the crossover operators. but octopus is meant to keep it general for the moment - maybe there's a way for an interface to code those things yourself..!?
2) elite size = SPEA-2 archive size, yes. the rate depends on your convergence behaviour i would say. i usually start off with at least half the size of the population, but mostly the same size (as it is hard-coded in the new version, i just realize) is big enough.
4) the non-dominated front is always put into the archive first. if the archive size is exceeded, the least important individual (the significant strategy in SPEA-2) are truncated one by one until the size is reached. if it is smaller, the fittest dominated individuals are put into the elite. the latter happens in the beginning of the run, when the front wasn't discovered well yet.
3) yes it is. this is a custom implementation i figured out myself. however i'm close to have the HypE algorithm working in the new version, which natively has got the possibility to articulate perference relations on sets of solutions.
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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