then passed to the file3dm.Write() Method when it's used? Turns out it will work in the Visual Studio IDE perfectly well like this, Now I'm just sorting out the best way to create a surface.
If I can ask one more question, what does file.Polish() do?
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Rhino.Geometry;
using Rhino.FileIO;
using Rhino.Collections;
using Rhino;
namespace NurbsExample
{
class Program
{
static void Main(string[] args)
{
string output = "C:/WorkingFileExample.3dm";
RunScript(output);
}
private static void RunScript(string path)
{
File3dm file = new File3dm();
file.Polish();
for (int j = 0; j<=10; j++)
{
file.Objects.AddLine(new Line(j, 0, 5 - j, 5 + j, 0, j));
}
File3dmWriteOptions options = new File3dmWriteOptions();
options.SaveAnalysisMeshes = false;
options.SaveRenderMeshes = false;
options.SaveUserData = true;
file.Write(path, options);
}
}
}…
Added by Henry Jarvis at 6:33am on October 7, 2015
..
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.
…
This is the actual reason I'm going through all this. I want to develop an algorithm that can be applied consistently and produce good results.
Here is a a little background. I'm working on my master's thesis in structural analysis. My thesis is on seismic behaviour of a roman temple in Portugal. I will be using a method of analysis suitable for block structures called the discrete element method. I am using a commercial code called 3DEC for this.
Now in order to the analysis I need to construct a 3D block model of my structure. I received a 3D scan of the entire structure (in *.wrl) format and spent a week trying to clean it up and slice it into the blocks that make up the structure. Now I want to use the scanned geometry of the blocks and describe a simplified prism around each that will represent the block in my analysis. I've attached a file with one of the columns in the temple. I think (at least with my tests so far) that it is representative of the all the blocks I'm dealing with.
Now my criteria for creation of the blocks:
I would like the contact area between the blocks to be as close as possible to the actual drum contact area,
I would like to get the volume of the blocks to be as close as possible (secondary to the contact area) to the volume of the actual drums in order to insure that the weight distribution in the structure is as close to reality as possible,
I would like the shape of the contact area to be as close to reality as possible
I order to satisfy all these requirements, I've done the following in my grasshopper file:
I take a section at the top and bottom of each of the drum meshes. I use this to extract the contact outline at the top and bottom of the drum. This is sometimes problematic and requires me to clean up the model and remove features that interfere.
Next I take each surface and try to fit a minimum circle around it. I try to do this because in my mind this is the best possible way to find the actual centre of the drum when there is cut outs and deterioration. This works well as long as more than half of the contact surface is still in its circular shape (third block from bottom in the example file doesn't satisfy this requirement and thus causes problems).
Knowing the centre, I use an algorithm I created in VB to search for one of the flutes on the contact profile. My ideas is that if I can find one of the flutes, I can then find the others by just going around at 30 degrees (there are 12 flutes) and find the location of all the flutes. In the VB code I've tried to explain my algorithm so I won't explain it here. I also think this algorithm is needlessly complicated and stupid as I'll explain later.
Once I've got one of the flutes, I just find the intersection of a line with at every 30 degrees with the outline curve.
Having all (12) points around the perimeter, I use an loop to scale the shape around the centre of the circle I found in step 1 to get the area within a tolerance value of the actual contact area (satisfying requirement 1). I was using HoopSnake before, but it required resetting every time so I decided to write my own thing.
I then connect the points on both top and bottom to get a solid block.
Now the problems are as follows:
Sometimes the algorithm doesn't find the best location as the starting point. As I said an important thing is that the circle is tangent to the flutes and that is true only if the column profile is larger than a half-circle.
The software I use requires convex blocks. I've tried to remedy this by using convex hull component before step 5 to insure the surfaces are convex.
I'm having issues sometimes with the alignment of top and bottom points. I think I just need to implement a component that sorts the points around a single basis so that there is no twisting.
I've been experimenting with convex hull as a general approach for defining the corner points, but I'm having problem take the convex hull curve and breaking it into a 12 sided polygon, preserving as much as possible the location of the flutes and the general shape of the contact surface.
I'm really sorry about the long post and complicated question. I hope someone can give some pointers on what I could try. I understand that this is not an easy question and that it is more a question of doing something rather than asking about grasshopper itself. My goal is to have an algorithm that I can explain as a general method for others to use in the future when dealing with these structures. This is only a small minor part of my thesis (the analysis is what is important) but it is taking a lot of time to figure out.
If you have any other questions, I would be more than happy to provide a better explanation. In the file I have created a region with all my input parameters. You can choose a different mesh from that point and change various settings. I hope that is self-explanatory.
Thanks for all your help,
Ali
BTW: I'm really sorry for the poor way I've done this stuff so far. I'm not a programmer and apart from some small macros in Excel I don't know much about this stuff. To add to that, I've just started with Rhino and Grasshopper about five days ago after almost pulling out all my hair trying to do this with AutoCAD!…
o my python component returning null despite running fine in the standalone python editor (i.e.: not through grasshopper).The original python script is as follows:
import randomimport rhinoscriptsyntax as rsrs.EnableRedraw(False)
def placeBuildings(curve, distance): pts=rs.DivideCurveLength(curve,5) counter=0 for myPoint in pts: counter=counter+1 #get the parmeter f current positision param=rs.CurveClosestPoint(curve,myPoint) #get teh tangent of this parameter tangent=rs.CurveTangent(curve,param) #calculate the angle of the tangent angle=rs.Angle((0,0,0),tangent) randomNumber=random.uniform(1,5) heightOfBuilding=random.uniform(4,40) rect=rs.AddRectangle(rs.WorldXYPlane(),randomNumber,2) rs.MoveObject(rect,(0,randomNumber,0)) hull=rs.ExtrudeCurveStraight(rect,(0,0,0),(0,0,heightOfBuilding)) rs.RotateObject(hull,(0,0,0),angle[0]) rs.MoveObject(hull,myPoint) #if counter%4: #rs.AddCircle(myPoint,3) #selection of curve#curveParameter=rs.GetCurveObject("sel curve")#curve=curveParameter[0]
curves=rs.GetCurveObject("select streets",4)distance=rs.GetInteger("distance?",4)for curve in curves: placeBuildings(curve,distance) rs.ReverseCurve(curve) placeBuildings(curve,distance)
When placed in grasshopper it is the following:
import randomimport rhinoscriptsyntax as rs
#randomNumber=random.uniform(1,5)#rs.AddCircle((0,randomNumber,0), 2)
def placeBuildings(curve, distance): pts=rs.DivideCurveLength(curve, 5) counter=0 for myPoint in pts: counter=counter+1 #get the parmeter f current positision param=rs.CurveClosestPoint(curve,myPoint) #get teh tangent of this parameter tangent=rs.CurveTangent(curve,param) #calculate the angle of the tangent angle=rs.Angle((0,0,0),tangent) randomNumber=random.uniform(1,5) heightOfBuilding=random.uniform(4,40) rect=rs.AddRectangle(rs.WorldXYPlane(),randomNumber,2) rs.MoveObject(rect,(0,randomNumber,0)) hull=rs.ExtrudeCurveStraight(rect,(0,0,0),(0,0,heightOfBuilding)) rs.RotateObject(hull,(0,0,0),angle[0]) rs.MoveObject(hull,myPoint)
#selection of curve#curveParameter=rs.GetCurveObject("sel curve")#curve=curveParameter[0]
curves=xdistance=y
for curve in curves: placeBuildings(curve,distance) rs.ReverseCurve(curve) placeBuildings(curve,distance)
I am unsure why there is no error being returned yet I cannot achieve any result other than null. Maybe someone could look at the script and tell me what is going wrong? I'm hoping to solve this before next Thursday so I might be asking for too much.
Much Appreciated.-A…
Added by Adem O'Byrne at 11:45am on October 9, 2014
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.
…
What is it?Bumblebee is a set of user objects which connect Microsoft Excel and Grasshopper.
The current component set allows for not just the transfer of data back and forth between GH and XL but giv
t. So here we go!
1. Honeybee is brown and not yellow [stupid!]...
As you probably remember Honeybee logo was initially yellow because of my ignorance about Honeybees. With the help of our Honeybee expert, Michalina, now the color is corrected. I promised her to update everyone about this. Below are photos of her working on the honeybee logo and the results of her study.
If you think I'm exaggerating by calling her a honeybee expert you better watch this video:
Thank you Michalina for the great work! :). I corrected the colors. No yellow anymore. The only yellow arrows represent sun rays and not the honeybee!
2. Yellow or brown, W[here]TH Honeybee is?
I know. It has been a long time after I posted the initial video and it is not fun at all to wait for a long time. Here is the good news. If you are following the Facebook page you probably now that the Daylighting components are almost ready.
Couple of friends from Grasshopper community and RADIANCE community has been helping me with testing/debugging the components. I still think/hope to release the daylighting components at some point in January before Ladybug gets one year old.
There have been multiple changes. I finally feel that the current version of Honeybee is simple enough for non-expert users to start running initial studies and flexible enough for advanced users to run advanced studies. I will post a video soon and walk you through different components.
I think I still need more time to modify the energy simulation components so they are not going to be part of the next release. Unfortunately, there are so many ways to set up and run a wrong energy simulation and I really don’t want to add one new GIGO app to the world of simulation. We already have enough of that. Moreover I’m still not quite happy with the workflow. Please bear with me for few more months and then we can all celebrate!
I recently tested the idea of connecting Grasshopper to OpenStudio by using OpenStudio API successfully. If nothing else, I really want to release the EnergyPlus components so I can concentrate on Grasshopper > OpenStudio development which I personally think is the best approach.
3. What about wind analysis?
I have been asked multiple times that if Ladybug will have a component for wind study. The short answer is YES! I have been working with EFRI-PULSE project during the last year to develop a free and open source web-based CFD simulation platform for outdoor analysis.
We had a very good progress so far and our rockstar Stefan recently presented the results of the work at the American Physical Society’s 66th annual DFD meeting and the results looks pretty convincing in comparison to measured data. Here is an image from the presentation. All the credits go to Stefan Gracik and EFRI-PULSE project.
The project will go live at some point next year and after that I will release the Butterfly which will let you prepare the model for the CFD simulation and send it to EFRI-PULSE project. I haven’t tried to run the simulations locally yet but I’m considering that as a further development. Here is how the component and the logo looks like right now.
4. Teaching resources
It has been almost 11 months from the first public release of Ladybug. I know that I didn't do a good job in providing enough tutorials/teaching materials and I know that I won’t be able to put something comprehensive together soon.
Fortunately, ladybug has been flying in multiple schools during the last year. Several design, engineering and consultant firms are using it and it has been thought in several workshops. As I checked with multiple of you, almost everyone told me that they will be happy to share their teaching materials; hence I started the teaching resources page. Please share your materials on the page. They can be in any format and any language. Thanks in advance!
I hope you enjoyed/are enjoying/will enjoy the longest night of the year. Happy Yalda!
Cheers,
-Mostapha
…