2: https://vimeo.com/107502226
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Hi all,
1. Chris, Chien Si and I will present Ladybug and Honeybee at IBSA-USA NYC this Thursday (August 21st). The presentation will include some of the latest developments that we are working on. If you are interested to know more about some of the new developments and see some of the workflows and you are around New York then just stop by. If can't attend in person you can still watch the presentation online. Check the links below. (Make sure to register by Wednesday if you are attending in person.)
2. We would like to show some of the works that you have done with Honeybee and Ladybug during the presentation so if there is anything that you think is interesting and can be presented publicly send it to us at thisisladybug@gmail.com or just post it here. Make sure to let us know who do you want us to credit the image.
3. That's it for now. I copy the information about the presentation below and hope to see some of you there. Thanks for your help and support.
Cheers,
Mostapha
IBPSA-USA New York Regional Chapter presents:
Parametric Modeling Tools | Ladybug and Honeybee
Location: Thornton Tomasetti, 44 East 27th street (between Madison and Park)
Date & Time: Thursday, August 21, 2014 - 6:00-7:30 PM.
6:00-6:30 PM Networking
6:30-7:30 PM Ladybug and Honeybee
Mostapha Sadeghipour Roudsari, Thornton Tomasetti
Chris Mackey, MIT
Chien Si Harriman, Terabuild
7:30-7:45 PM Q & A
Click here to register**: https://attendee.gotowebinar.com/register/6507378565592582402
**Please register at least a day in advance if you wish to attend in person
Descriptions
Ladybug + Honeybee
Ladybug and Honeybee are open source environmental plugins for Grasshopper that help architects and engineers create an environmentally-conscious architectural design.
Ladybug imports standard EnergyPlus Weather files (.EPW) into Grasshopper and provides a variety of 3D interactive graphics to support the decision-making process during the initial stages of design. The plugin also provides further support for designers as they test their initial design options with radiation, sunlight-hour, and shading analyses. Integration with Grasshopper allows for an almost instantaneous feedback and, since the plugin runs within the design environment, the information and analyses are interactive.
Honeybee connects Grasshopper3D to EnergyPlus, Radiance, Daysim and OpenStudio for building energy and daylighting simulation. The Honeybee project intends to make many of the features of these simulation tools available in a parametric way. Just as users have made changes to geometry for years in Grasshopper, now users can parameterize system types, zoning schemes, schedules of operation, daylight sensor placement and controls - all of the “hardcore” simulation parameters that have never been exposed to parametric modeling tools.
https://www.facebook.com/LadyBugforGrasshopper http://www.grasshopper3d.com/group/ladybug
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1)
Hi Clemens I've analysed a plate structure using Karamba and wanted to do a convergence analysis on results computed as a function of the number of elements.
Now, when strictly looking at the result magnitudes of internal energy (IE) and maximum displacement (w_max), it's acceptable, that their relative deviations are very small. But I cannot explain the tendencies of their graphs. From what I know, FEM should always compute underestimated results when compared to analytical solutions. So I don't understand why both the IE and w_max seem to be decreasing for an increasing number of elements.
But my main concern is the behaviour of the peak moment, it seems to be simply hill climbing untill suddenly a singularity kicks in. I initially wanted to use the peak moment as a fitness value for optimisation, but with this behaviour, I don't think that would make sense. I've attached my GH file as well.
It would be much appreciated if you could enlighten me on these subjects. Cheers Daniel Andersen
2)
Hi Daniel,
I could not run your definition because I have not all the plug-ins installed that you use.
You are basically right that the displacement should increase with a finer mesh. However the result of the shell analysis also depends on the shape of the triangles (well formed vs. very distorted). In order to test this, I think it would be interesting to use a very simple example (e.g. rectangular plate with one column) where you can easily control mesh generation. Would you like to start a discussion on this in the karamba group at http://www.grasshopper3d.com/group/karamba?
It is not a good idea to use the bending moment at a singularity for optimization because the result will be heavily mesh dependent. Also real columns do have a certain diameter and modeling them as point supports introduces an error.
Best,
Clemens
3)
oh, and by the way!
Here's some relevant literature on handling peak moments: https://books.google.dk/books?id=-5TvNxnVMmgC&pg=PA219&lpg=PA219&dq=blaauwendraad+plates+and+fem&source=bl&ots=SdDcwnrSA1&sig=6HulPmKNIhqKx4_rGxitteMC4CU&hl=da&sa=X&ved=0CDEQ6AEwA2oVChMIg66k0LPaxgIVgY1yCh1KPAeY#v=onepage&q=chapter%2014&f=false (Blaauwendraad, J., 2010. Plates and FEM : Surprises and Pitfalls, see Chapter 14) It would be great if a feature dealing with peak moments could be incorporated in Karamba. In my work, I ended up exporting my models to Robot in order to verify the moment values. Best, Daniel
4)
Hi Daniel,
thank you for your reply and the link to Blaauwendraads excellent book!
At some point I hope to include material nonlinearity in Karamba which will help in dealing with stress singularities.
If you want you could open a discussion with a title like 'moment peaks in shells at point-supports'. Then we could copy and paste the text of our conversation into it.
Best,
Clemens
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me of the dimensions that changed ( become Diagonal after they were Vertical or Horizontal)
I sometime use Record History in rhino for saving time, but when I change some points of curves or trim curves , I have problems with dimensions (see the two pictures below).
Problem 2 :
After trimming , only two dimensions should be changed depending on their place in changed curves . But what happens is that all the dimensions become crazy!!!!!!
I always use Aligned dimension in rhino. Now I know that dimensionsdo not exist in grasshopper. So I ask you if we have expertise in BV , C#, can we create a script for dimensions or is it impossible ??
If we can , I only need Aligned dimension.
I hope that I find or create a script that can define all points: start and end of curve ribs and create dimensions from grasshopper to rhino directly with or without the ability to change automatically .
Thank you
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y anyway ;))
Since 2014 i begun to get back into the construction biz for some dozen main reasons, one of them being the highly increased availability of this kind of software "power", and robotics.
first project ended by 1stQ 2015 was focused on the development of a parametric block for construction. (almost sure the first parametric product designed in Uruguay, and probably one of the few first of this kind globally...)
Far from being a complicated model. In fact the standard model is extremely simple, key thing is that is fully parametric...
dimensions, materials, textures, colors... and so on
second key thing is that the main common component of the blocks (an EPS core) is robotically machined...
the blocks are the base of a construction system (oriented mainly - though not restricted only - to residential buildings) that
- is based on digital models, tendentially to be used in parametric models of buidings
- lab tested to prove to be 1.5 times as compression resistant than traditional bricks and blocks. (autoportability up to two stories buildings)
- has recently proved (due to size) to be 300% more efficient than the classic and 200% more efficient than steel frame in (our country official figures)
check it out here
--
https://drive.google.com/file/d/0B1TRxxgF_sEnQnZrTkZGbUx3cmM/view
--
- and it's aimed to be mass produced and handled by robots...
this project ended on 1H 2016
and i filed 4 patents in the process.
3 of them of mechanical devices designed as extensions for a cnc machine i own
and the fourth (
the patent related specifically with the blocks ) included a dozen of innovations (believe me...i have almost 15 yrs in the biz, and are coool stuff...)
along the project I've been working with inventor, even knowing in advance it will lack the kind of features I wanted to program many things... (lisp, VB, etc.... all same species of -prehistoric - animals) to leverage the tool to the sky - and far beyond... -
but was an alternative valid by that time because it allows the implementation of some form of parametric models, had a local representative and some supposedly skilled guys in the neibourhood....
but life is hard... and none of the latter two rendered me any significant help
so I had to take the tour myself...
- mind i never regret to do things that others cant -
and finish what i start
this one was a great project for many figures... and ended with more results than the ones commited to accomplish...
... some more history here ....
then because of a customer who brought a ZHA project ! to quote..., I crossed with rhino, and then met GH again to notice to my great joy and pleasure, in what kind of animal it had developed...
since money talks I'm investing hard on getting up to the expectations, and beyond as i usually do...
and thats how we met..
2017-2018 it's the time frame to build two robots. first one is a prototype to handle the k-nano blocks in the production process, delivery AND at the construction site ( a "smart crane" we nicknamed...)
the other one is the first prototype of robot to assist in the fabrication (smart blocker we called it to be creative ! ;))
then by 2018-2019 i'll be making a "kinda contour crafter" machine to complete the pie :) (you'll be interested on this..)
i guess you already know what all this has to do with GH...
i already have all the components i can imagine to do almost all i ever wanted to do in relation to this set of projects
but in almost a single tool !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
i can design, animate, render, optimize, simulate and even robotic simulate..
so, i have to ask...
is there a chance you might be interested in helping us in some projects we are starting on march and june 2017 (8 and no more than 18 months of duration respectively) ?
sent you a friend request, for the case you might be interested to continue by e-mail...
in any case many thanks for your help and inspiration !
best regards !
long happy marriage, and large figures bank account !
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The problem is that using the index, adding a activies, the next activies change the index and then the link is wrong.
example: I need to connect to hotel function with house function, therefore i have 0 and 4 index in my panel.. So i have to extract the index linked to the alphabetical value to be able to draw lines between the points associated to the names of activities. Now if i add a new string between the values, the house activity hasn't the original index 4 but the new index 5. So the link will be not created between hotel and house but hotel e new activity in the index 4.
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ou will see a list of potential matches, sorted from most relevant to least relevant:
Some components and objects support initialisation codes, which means you can assign certain values directly from the popup box. You can do this by adding an equals symbol after the name and then the value you wish to assign. For example, the [Curve Offset] component allows you to specify the offset distance via the popup box by typing =5 after the offset command:
However the popup box also supports a set of special formats that allow you to create specific objects without even typing their names. As of 0.9.0077 (which hasn't been released yet at the time of writing) you can use the following shortcuts to create special objects. In the notation below optional parts of a format will be surrounded by square brackets and hashes (#) will be used to indicate numeric values. So #,#[,#] means;
at least two numeric values separated by a comma, with an optional second comma and third number.
A complete list of special formats (not all of these are supported yet in 0.9.0076):
"∙∙∙ If the format starts with a double quote, then the entire contents (minus any other double quotes) will be placed into a Text Panel.
//∙∙∙ If the format starts with two forward slashes, then the entire contents will be placed in a Text Panel.
~∙∙∙ If the format starts with a tilde, then the entire contents will be placed in a Scribble object.
#,#[,#] If the format contains two or three numerics separated by commas, a Point parameter will be created with the specified coordinates.
+[#] If the format starts with a plus symbol followed by a numeric, then an Addition component will be created.
-[#] If the format starts with a minus symbol followed by a numeric, then a Subtraction component will be created.
*[#] If the format starts with an asterisk symbol followed by a numeric, then a Multiplication component will be created.
/[#] If the format starts with a forward slash symbol followed by a numeric, then a Division component will be created.
\[#] If the format starts with a backward slash symbol followed by a numeric, then an Integer Division component will be created.
%[#] If the format starts with a percent symbol followed by a numeric, then a Modulus component will be created.
&[∙∙∙] If the format starts with an ampersand symbol, then a Concatenation component will be created.
=[∙∙∙] If the format starts with an equals symbol, then an Equality component will be created.
<[*] If the format starts with a smaller than symbol, then a Smaller Than component will be created.
>[*] If the format starts with a larger than symbol, then a Larger Than component will be created.
[# *] Pi If the format contains the text "Pi" with an optional multiplication factor, then a Pi component will be created.
# If the format can be evaluated as a single numeric value, then a Slider will be created with the specified initial value and sensible™ lower and upper limits.
#<# If the format contains two numerics separated by a smaller than symbol, a Slider with the specified limits will be created. The initial slider value will be equal to the lower limit.
#<#<# If the format contains three numerics separated by a smaller than symbol, a Slider with the specified limits will be created. The initial slider value will be the value in the middle.
#..# If the format contains two numerics separated by two or more consecutive dots, a Slider with the specified limits will be created. The initial slider value will be equal to the lower limit.
#..#..# If the format contains three numerics separated by two or more consecutive dots, a Slider with the specified limits will be created. The initial slider value will be the value in the middle.
#/#/[#] If the format contains two or three numerics separated by forward slashes, a Calendar object will be created. The order of value is day/month/year. If year is omitted then the current year is used. Note that a second slash is required because #/# is interpreted as a number and thus results in a Slider.
#:#[:#] [am/pm] If the format contains at least two numerics separated by a colon, a Clock object is created. Seconds are optional, as are am/pm suffixes.
f([...[,...[,...]]]) [= *]If the format starts with a lower case f followed by an opening bracket, an Expression component is created. A list of comma separated arguments can be provided as inputs, and anything after the optional equals symbol becomes the expression string.
Note that decimal places will be harvested from formats that indicate sliders. I.e. the format 0..2..10 is not the same as 0..2..10.00, as the former will create an integer slider from zero to ten whereas the latter will create a floating point slider with two decimal places from zero to ten.…
Added by David Rutten at 3:24pm on February 18, 2013
ndard length elements without any cutting, and using only simple connections, such as cable ties or scaffold swivel couplers.
To summarize the approach I present here:
Design an initial shape
Remesh this form so that the edges are all roughly the length of the tubes we will use to build the structure
Rotate and extend the edges of this mesh to create the crossings
Apply a relaxation to optimize the positions of the tubes for tangency
demo_reciprocal_structures.gh
Initial form
In this example I show how to apply this system to a simple sphere. You can replace this with any arbitrary shape. It can be open or closed, and have any topology.
Remeshing
The new ReMesher component takes an input mesh, and a target edge length, and iteratively flips/splits/collapses edges in order to achieve a triangulated mesh of roughly equal edge lengths.
Press the Reset button to initialize, then hold down the F5 key on your keyboard to run several iterations until it has stabilized. (F5 just recomputes the solution, and this can be a quick alternative to using a timer)
Once the remeshing is complete, bake the result into Rhino and reference it into the next part of the definition (I recommend doing this rather than connecting it directly, so that you don't accidentally alter the mesh and recompute everything downstream later).
Alternatively you can create your mesh manually, or using other techniques.
Rotate and Extend
We generate the crossings using an approach similar to that described by Tomohiro Tachi for tensegrity structures here:
http://www.tsg.ne.jp/TT/cg/FreeformTensegrityTachiAAG2012.pdf
Using the 'Reciprocal' component found in the Kangaroo mesh tab, each edge is rotated about an axis through its midpoint and normal to the surface, then extended slightly so that they cross over.
By changing the angle you can change whether the fans are triangular or hexagonal, and clockwise or counter-clockwise.
Choose values for the angle and scaling so that the lines extend beyond where they cross, but not so far that they clash with the other edges.
Note that each rod has 4 crossings with its surrounding rods.
There are multiple possibilities for the over/under pattern at each 'fan', and which one is used affects the curvature:
A nice effect of creating the pre-optimization geometry by rotating and extending mesh edges in this way is that the correct over/under pattern for each fan gets generated automatically.
Optimization for tangency
We now have an approximate reciprocal structure, where the lines are the centrelines of our rods, but the distances between them where they cross vary, so we would not actually be able to easily connect the rods in this configuration.
To attach the rods to form a structure, we want them to be tangent to one another. A pair of cylinders is tangent if the shortest line between their centrelines is equal to the sum of their radii:
Achieving tangency between all crossed rods in the structure is a tricky problem - if we move any one pair of rods to be tangent, we usually break the tangency between other pairs, and because there are many closed loops, we cannot simply start with one and solve them in order.
Therefore we use a dynamic relaxation approach, where forces are used to solve all the tangency constraints simultaneously, and over a number of iterations it converges to a solution where they are all met. The latest Kangaroo includes a line-line force, which can be used to pull and push pairs of lines so that they are a certain distance apart. Each rod is treated as a rigid body, so forces applied along its length will cause it to move and rotate.
The reciprocal component uses Plankton to find the indices of which lines in the list cross, which are then fed into the force for Kangaroo. We also use springs to keep each line the same length.
If the input is good, when we run the relaxation (by double clicking Kangaroo and pressing play), the rods should move only a little. We can see whether tangency has been achieved by looking at the shortest distance between the centerlines of the crossing rods. When this is twice the rod radius, they are tangent. Wait for it to solve to the desired degree of accuracy (there's no need to wait for 1000ths of a millimeter), and then press pause on the Kangaroo controller and bake the result.
The radius you choose for the pipes, curvature of the form and length of the edges all affect the result, and at this stage you may need to tweak these input values to get a final result you are happy with. If you find the rods are not reaching a stable solution but are sliding completely off each other, you might want to try adding weak AnchorSprings to the endpoints of the lines, to keep them from drifting too far from their original positions.
For previewing the geometry during relaxation I have used the handy Mesh Pipe component from Mateusz Zwierzycki, as it is much faster than using actual surface pipes.
To actually build this, you then need to extract the distances along each rod at which the crossings occur, and whether it crosses over or under, mark the rods accordingly, and assemble (If there is interest I will also clean up and post the definition for extracting this information). While this technique doesn't require much equipment, it does need good coordination and numbering!
There is also a ReciprocalStructure user object component that can be found in the Kangaroo utilities tab, which attempts to apply steps 3 and 4 automatically. However, by using the full definition you have more control and possibility to troubleshoot if any part isn't working.
The approach described here was first tested and refined at the 2013 Salerno Structural Geometry workshop, lead by Gennaro Senatore and myself, where we built a small pavilion using this technique with PVC tubes and cable ties. Big thanks to all the participants!
Finally - this is all very experimental work, and there are still many unanswered questions, and a lot of scope for further development of such structures. I think in particular - which of the relative degrees of freedom between pairs of rods are constrained by the connection (sliding along their length, bending, and twisting) and how this affects the structural behaviour would be interesting to examine further.
Steps 3 and 4 of the approach presented above would also work with quad meshes, which would have different stability characteristics.
There is also the issue of deformation of the rods - as the procedure described here solves only the geometric question of how to make perfectly rigid straight cylinders tangent. The approach could potentially be extended to adjust for, or make use of the flexibility of the rods.
I hope this is useful to somebody. Please let me know if you do have a go at building something using this.
Any further discussion on these topics is welcome!
Further reading on reciprocal structures:
http://vbn.aau.dk/files/65339229/Three_dimensional_Reciprocal_Structures_Morphology_Concepts_Generative_Rules.pdf
http://www3.ntu.edu.sg/home/cwfu/papers/recipframe/
http://albertopugnale.wordpress.com/2013/04/05/form-finding-of-reciprocal-structures-with-grasshopper-and-galapagos/
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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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