bsp;
-Vehicle elements (3D objects and a component for custom vehicles; models from Google Warehouse)
-Traffic Velocity Graphs, drawn on every trajectory curve (allow custom graphs drawn)
-Traffic regulation elements (such as Traffic Lights and Stop Signals) and traffic density
-Particle Systems on trajectory curves, just to manage the traffic regulations and avoid collisions based on security distances
-Traffic Vehicle Animation Modes (Dots, Bounding Boxes or complex Meshes with attributes for final rendering (Giulio Piacentino´s Render Animation)
-Vehicle Lights and Vehicle Sights, to make visual studies
Team:
-Sergio del Castillo Tello (Doctor No, lead programmer)
-Everyone that wants to be involved, support.. these tools
The development of Roadrunner is planned to take part within a Research Group Program at ETSAM (University of Architecture in Madrid); This forum group is created just to test the interest of the community, while we keep on developing (it is still being tested), probably we will share the whole thing in the future. Cheers!
Traffic Cluster Scheme
Traffic Elements
Traffic Urban Systems
Vehicle Elements
Roadrunner - overview
Roadrunner 0 Basics
Roadrunner 1 Modes
Roadrunner 2 Elements
Roadrunner 3 Urban Systems…
peuvent se diviser une surface avec ne importe quel motif imaginable. 3. Ici, je fournir un moyen de le faire via Lunchbox ... cela fonctionne mais il est fixe et donc nous avons besoin de jouer avec des arbres de données afin de créer le motif approprié par cas. 4. L'autre composante est un joint C # qui fait beaucoup de choses autres que de diviser ne importe quelle collection de points avec de nombreux modèles (voir le modèle ANDRE que je ai fait pour vous). 5. Vous devez décomposer une polysurface en morceaux afin de travailler sur les subdivisions. 6. Je donne une autre définition ainsi que pourrait agir comme un tutoriel sur la façon de traiter des ensembles de points via des composants de GH standards et des méthodes classiques.
Avertissez si tous ceux-ci apparaissent floue pour vous: Si oui, je pourrais écrire une définition utilisant des composants de GH classiques - mais vous perdrez les variations de motifs de division.
mieux, Peter
…
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.
…
rmation?" I know that this can already be accomplished using the brilliant Kangaroo plugin, but I wanted a simpler and faster (yet still accurate) single component that could replicate this unique curve using a variety of inputs: the length of the rod/wire, the width/distance between the endpoints, the height of the bend, and the tangent angle at the start. I also wanted make the unknowns (such as height if only length and width are known) easily accessible for plugging into additional components.
The resulting script, being an all-in-one solution, is somewhat unwieldy, but it could easily be broken down into smaller components (custom .gha's which I don't have the ability to code). If someone wants to tackle this, please do! I'm not an expert coder by any means, and as this was only my second time diving into Grasshopper scripting, if the script seems somewhat strange, that's probably why. I did try to comment the code pretty well though. Here's the full description:
--------------------------------------------------
DESCRIPTION: This beast creates the so-called 'elastica curve', the shape a long, thin rod or wire makes when it is bent elastically (i.e. not permanently). In this case, force is assumed to only be applied horizontally (which would be in line with the rod at rest) and both ends are assumed to be pinned or hinged meaning they are free to rotate (as opposed to clamped, when the end tangent angle is fixed, usually horizontally). An interesting finding is that it doesn't matter what the material or cross-sectional area is, as long as they're uniform along the entire length. Everything makes the same shape when bent as long as it doesn't cross the threshold from elastic to plastic (permanent) deformation (I don't bother to find that limit here, but can be found if the yield stress for a material is known).
Key to the formulas used in this script are elliptic integrals, specifically K(m), the complete elliptic integral of the first kind, and E(m), the complete elliptic integral of the second kind. There was a lot of confusion over the 'm' and 'k' parameters for these functions, as some people use them interchangeably, but they are not the same. m = k^2 (thus k = Sqrt(m)). I try to use the 'm' parameter exclusively to avoid this confusion. Note that there is a unique 'm' parameter for every configuration/shape of the elastica curve.
This script tries to find that unique 'm' parameter based on the inputs. The algorithm starts with a test version of m, evaluates an expression, say 2*E(m)/K(m)-1, then compares the result to what it should be (in this case, a known width/length ratio). Iterate until the correct m is found. Once we have m, we can then calculate all of the other unknowns, then find points that lie on that curve, then interpolate those points for the actual curve. You can also use Wolfram|Alpha as I did to find the m parameter based on the equations in this script (example here: http://tiny.cc/t4tpbx for when say width=45.2 and length=67.1).
Other notes:
* This script works with negative values for width, which will creat a self-intersecting curve (as it should). The curvature of the elastica starts to break down around m=0.95 (~154°), but this script will continue to work until M_MAX, m=0.993 (~169°). If you wish to ignore self-intersecting curves, set ignoreSelfIntersecting to True
* When the only known values are length and height, it is actually possible for certain ratios of height to length to have two valid m values (thus 2 possible widths and angles). This script will return them both.
* Only the first two valid parameters (of the required ones) will be used, meaning if all four are connected (length, width or a PtB, height, and angle), this script will only use length and width (or a PtB).
* Depending on the magnitude of your inputs (say if they're really small, like if length < 10), you might have to increase the constant ROUNDTO at the bottom
REFERENCES: {1} "The elastic rod" by M.E. Pacheco Q. & E. Pina, http://www.scielo.org.mx/pdf/rmfe/v53n2/v53n2a8.pdf {2} "An experiment in nonlinear beam theory" by A. Valiente, http://www.deepdyve.com/lp/doc/I3lwnxdfGz {3} "Snap buckling, writhing and Loop formation In twisted rods" by V.G.A. GOSS, http://myweb.lsbu.ac.uk/~gossga/thesisFinal.pdf {4} "Theory of Elastic Stability" by Stephen Timoshenko, http://www.scribd.com/doc/50402462/Timoshenko-Theory-of-Elastic-Stability (start on p. 76)
INPUT: PtA - First anchor point (required) PtB - Second anchor point (optional, though 2 out of the 4--length, width, height, angle--need to be specified) [note that PtB can be the same as PtA (meaning width would be zero)] [also note that if a different width is additionally specified that's not equal to the distance between PtA and PtB, then the end point will not equal PtB anymore] Pln - Plane of the bent rod/wire, which bends up in the +y direction. The line between PtA and PtB (if specified) must be parallel to the x-axis of this plane
** 2 of the following 4 need to be specified ** Len - Length of the rod/wire, which needs to be > 0 Wid - Width between the endpoints of the curve [note: if PtB is specified in addition, and distance between PtA and PtB <> width, the end point will be relocated Ht - Height of the bent rod/wire (when negative, curve will bend downward, relative to the input plane, instead) Ang - Inner departure angle or tangent angle (in radians) at the ends of the bent rod/wire. Set up so as width approaches length (thus height approaches zero), angle approaches zero
* Following variables only needed for optional calculating of bending force, not for shape of curve. E - Young's modulus (modulus of elasticity) in GPa (=N/m^2) (material-specific. for example, 7075 aluminum is roughly 71.7 GPa) I - Second moment of area (or area moment of inertia) in m^4 (cross-section-specific. for example, a hollow rod would have I = pi * (outer_diameter^4 - inner_diameter^4) / 32 Note: E*I is also known as flexural rigidity or bending stiffness
OUTPUT: out - only for debugging messages Pts - the list of points that approximate the shape of the elastica Crv - the 3rd-degree curve interpolated from those points (with accurate start & end tangents) L - the length of the rod/wire W - the distance (width) between the endpoints of the rod/wire H - the height of the bent rod/wire A - the tangent angle at the (start) end of the rod/wire F - the force needed to hold the rod/wire in a specific shape (based on the material properties & cross-section) **be sure your units for 'I' match your units for the rest of your inputs (length, width, etc.). Also note that the critical buckling load (force) that makes the rod/wire start to bend can be found at height=0
THANKS TO: Mårten Nettelbladt (thegeometryofbending.blogspot.com) Daniel Piker (Kangaroo plugin) David Rutten (Grasshopper guru) Euler & Bernoulli (the O.G.'s)
--------------------------------------------------
Edit: More on the math behind this here.
Cheers,
Will
…
Added by Will McElwain at 4:08pm on February 26, 2014
y (movement, protection, temperature regulation) but also the evolution of cultural expression precisely by exceeding the purely indexical performative relations. Designing not only for the needs but for the desires.
Computational couture looks at the creation of exclusive custom-fitted clothing (typical of haute couture) through the lens of a systemic approach, extending the sartorial techniques with 3D modeling and computation-based approaches developed in Rhinoceros and the visual programming environment Grasshopper.
Aim of the workshop is to exert, infuse and expand the sartorial sensibilities to body proportions and dress making into an algorithmic approach that loops through design and fabrication by means of laser cutting and 3d printing for the design and production of a garment. Participants will be divided in teams focusing on specific aspects of the garment related to the production technique (laser cutting or 3D printing).
////////////////////////////////////
WORKSHOP | calendar
Day 1
Introduction to algorithms and computational design for creative disciplines Basics of 3D modeling in Rhinoceros Basics of Grasshopper Introduction to basic sartorial techniques
Day 2 Testing design options for the dress in Grasshopper (tutored work)
Day 3 Fabrication session . file preparation . parts testing and pre-assembly
Day 4 dress fabrication and assembly
Day 05 finalization of dress final presentation
////////////////////////////////////
WORKSHOP | registration
FEE FOR PARTICIPANTS
Early bird (until 4/5): 250 € Full fee (from 5/5 until 15/5): 350 €
The fee includes materials and fabrication. Plane tickets and accommodation are not included in the fee.
////////////////////////////////////
REGISTRATION (until 15/5/2015)
For registration please write at :
beyond@iaac.net
for more info visit:
http://beyond.iaac.net/?page_id=1620
…
umbers behave differently from the reals, in that when they are squared they give a negative result. They are written as multiples of the imaginary unit i, which is defined so that:
i*i=-1
Complex numbers are numbers which have two parts (hence the name complex) - a real part and an imaginary part.
For example:
3+4i,
or more generally:
a+bi, where a and b are some real numbers.
Well that's a definition, but I guess you might be wondering what is the point of them - I've not said anything yet about why they are interesting and useful...
Solving cubic equations was one of their first uses, but I doubt that is what most of you are interested in.
Where they really get fun is when you start looking at them geometrically.
The Argand plane is a setting that allows us to treat complex numbers a bit like vectors.
Each complex number a+bi defines a point relative to an origin (0,0), much the same as a vector with an x and y component.
Like vectors we can add and subtract them to get a new point.
But when we multiply them, unlike vectors, we add the angles (measured anti-clockwise from the positive real axis, also called the argument) and multiply the lengths (or the modulus of each number).
This all follows naturally as a consequence of the definition of i as the square root of minus one.
........
That is just dipping a toe into the great depths.
Complex number math, and in particular complex Analysis (calculus with complex numbers) is a vast subject that I obviously can't cover much of here.
If you are interested in learning more :
The Math department at Cal State Fullerton has some very nice Complex Analysis pages.
Chapters 5 and 6 of the film Dimensions covers complex numbers very visually. You can watch it online here, or read the description here.
Complex numbers on Wikipedia
on MathWorld
Hans Lundmark's complex analysis pages
The book Indra's Pearls is about making certain types of fractals with complex numbers, and includes a good introduction, along with lots of pseudocode.
To really engage with some of the true depth and power of complex numbers I particularly recommend the beautiful Visual Complex Analysis. This was the book that made me love this subject.
I'm really looking forward to seeing more designers make use of complex numbers. I think it is a wonderful tool. It is an advanced branch of mathematics, requiring some serious study to understand, but because of its strong geometric connections, I think relatively accessible to those who tend to think more visually. Now that David has included them in Grasshopper, starting to explore them should be easier than ever.…
Added by Daniel Piker at 4:38am on November 25, 2009
can work in any node of a given hierarchy tree (loaded in your work session) by making the node "active". "Nodes" can be other things as well (like workplane, clip definitions etc).
Why to do that weird thing? Well, think any design being "flat" > meaning that all objects are placed in a single file (and in a single layer). Not that good > although the items are present you barely can handle them (because power is nothing without control, he he).
Let's go one step further: we can start classifying objects in "groups" (like a directories/files organization in any O/S). This means, in MCAD speak, creating assemblies (a void thing kinda like a directory) that contain components/entities (kinda like files).
Several steps further we end up with severely nested "arrangements" of entities (an assembly could be parent of something and child of something else).
For instance, it could be rather obvious the logical classification of a "geodetic" (so to speak) structure like this : a 40000m2 "hangar" defining some thematic park.
I mean : a void master that owns 4 equal void segment sets that own 4 "legs" that own various geodesic structural members + cables + membranes + you name it etc etc.
Each "leg" owns the concrete base (Shared) and a rather complex set of objects.
Notice that some tensile membrane "fixture" combos (see above)...act as perimeter light fixtures as well...meaning that the membrane tension plate may could be a child of a void "light" parent...or may could be a "stand alone" assembly etc etc.
These arrangements can be internal (belonging in, say, a x node within the current active file) or external (belonging in a y node within another file). If they deal with the same (topologically speaking) object they define clusters of Shared entities (or variations)- where only the view transformation matrix changes (in the simple scenario, he he). For instance the disk shown above is a Shared Assembly that owns the bolts, the plates, the tension member etc etc. Selective Instancing allows modifying some attributes without affecting the topology (i.e. the geometry).
The whole (terrible) mess is controlled by some tree like "dialog" (in Catia is "transparent") that is called Structure Browser. By controlled I mean (1) display/display mode with regard any tree member combo/selection set (assembly and/or component) in any View (2) clip state control (3) active status (for modifications/variations) (4) workplane control (5) drag and drop ownership control (6) ....
Now...what if I would chan…
this occasion, but it could be converted for DT in no time). Requires some minutes more as regards ... some things, but the usual update is due to some days.
Bad news: it's C#
Good news: User's Manual :
1. That thing (the C#, not me) after sorting (in a "sequential way", so tho speak) the panels (their order was chaotic) allows you to start the massacre by locating a focus of interest (and the user controllable +/- Range derived from it).2. The Range is variable (obviously) and takes care not to exceed the indices of the panel list (OK, that's elementary).
3. If you click the right button (Sadistic Q: where is it? he he) things are deleted and a new constantly self-updating list is your new List. Thus the massacre of panels is totally controllable. An autoZoom thing is also included (free of charge, but it's a bit nerve braking). Zoom factor is variable as well.
4. Then you move over (via the index slider) and start the massacre again. Notice the change of Range.
5. If you turn begin to false (initialization) and then begin to true > start all over again.
6. The other C# thing allows you to increment the index slider in a rather more convenient way. It's a bit weird: it uses delegates (A delegate is an object that knows how to call a method) and events (An event is a construct that exposes just the subset of delegate features required for the broadcaster/subscriber model - but don't ask what this means, he he) in order to talk with your slider (with a defined NickName) and perform the required value control.
NOTE: without realizing it you've just (indirectly) asked one of the most important questions even exposed in this Noble Forum. I hear you : what question? Well ... wait some days for the mother of all threads: "Total control in collections on a per Item basis"
may the Force (the dark option) be with you (and me)
best, Peter…