s that I just can't quite figure out.
Zoom in of the lower left hand corner...
1. First off, I am not sure why two versions of the rectangles are showing, the original and the scaled versions from the image. This doesn't appear to be affecting my final results, so not a big deal, but would like to understand why there are two and get rid of the original rectangles if possible.
2. I would like to change the scaling factor of the the rectangles in the Y direction. They are currently scaling too small based on the image I provided. Is there a way to set a lower value minimum so that the rectangles are not quite so small. Please not that I am only wanting to scale the rectangles in the Y direction. I want the X to currently remain constant.
3. Lastly, I would like to offset the grid points in the y direction randomly so that the image does not seem so gridded. These should shift no more than 3/8 of the distance between the grid from the center point.
Desired Result:
Any help is greatly appreciated!…
Added by Josh Sawyer at 10:48am on September 17, 2017
o express my gratitude. I've been experimenting with your definitions (and still am), but let me extend my question.
Actually what I'm trying to achieve, is to recreate another project by Andrew Kudless, the spore lamp (I mentioned the Chrysalis at the beginning just because of the animation, which wasn't included in the Spore Lamp presentation).
Basically the spore lamp seems to me to be something like a preliminary study to the Chrysalis III project (I think it's a similar approach).
Andrew stated on his site that he used kangaroo for this project, so the Spore Lamp consists in my opinion either of a relaxed voronoi 3d diagram (b-rep, b-rep intersection) on a sphere which then has been planarized, or more likely it is a sort of relaxed facet dome.
The trick is to:
1. obtain a nicely-balanced voronoish diagram (or facet dome cells)
2. keep each cell/polyline planar (or force them with kangaroo to be planar) in order to move scale and loft them later on.
Here is what I have by now. (files: matsys spore lamp attempt)
That's the closest appearance that I got so far (simple move scale and loft of facet dome cells with the amount of transformations being proportional to the power of the initial cell area: bigger cell = bigger opening etc.) - with no relaxation of the diagram. But it's obviously not the same thing as the matsys design.
Here are some of my attempts of facet dome relaxation, but well, it certainly still not the right approach, and most importantly I don't know how to keep or force the cells to be planar after the relaxation.
1. pulling vertices to a sphere - no anchor points. That obviously doesn't make sense at all, but the relaxation without anchor points gives at the beginning a pattern that is closer to what I am looking for. (files: relaxation 01)
2. pulling vertices to a sphere - two faces of the initial facet dome anchored (files: relaxation 02)
3. pulling vertices to the initial geometry (facet dome) no anchor points (files: relaxation 03)
The cell pattern of the lamp kinda looks like this:
you can find it here: http://www.grasshopper3d.com/forum/topics/kangaroo-0-095-released?g...
Done with Plankton (of course without the "gradient increase" appearance), but in fact not, I took a look at Daniel Parker's Plankton example files, and it's not quite the same thing. Also the cells aren't planar...
The last problem is that during the relaxation attempts that I did, the biggest initial cells became enormous, and it's not like that in the elegant project by Andrew Kudless, that I'd like to achieve.
So to sum up:
Goal no 1: Obtain an elegant voronoi /facet dome cell pattern on a sphere (or an ellipsoid surface, whatever).
Goal no 2: Keep the cells planar in order to be able to loft them later and obtain those pyramidal forms, and assemble easily
Any ideas? Or maybe there's a completely different approach to that?…
make quad mesh usable with Kangaroo and with limited inputs parameters in order to simulate funicular structures like "Vaulted Willow" or "Pleated Inflation" from Marc Fornes and the Verymany.
Here is a first attempt script.
As inputs there are :
Lines_in, just lines, no duplicates, on XY plane could have Z values, but the algorithm works on a , on XY plane could have Z values, but the algorithm works on a flat representation.
Tolerance is used to glue lines when points are closer than tolerance
Width is the half width of the “roads” going through the network
Angle is the shape of the ends of the roads, 0° means flat end, 180° a totally rounded end
Deviation is the shift generating spikes or enabling to generate pleated geometry
N_u is the number of subdivision along the “roads”, image above with 3 subdivisions on the roads
N_u is the number of subdivision across the “roads”
Zbool if false everything is flat, if true the mesh is in 3d, best with angle = 180° or -180°
For the outputs there is the topology of the network (like Sandbox)
As outputs geometry are put on datatree, each branch represent a path on the road, above 3 paths, which are brep output.
Adding a diagonal there are now 4 paths so 4 branches
The mesh M goes with F which are fixed points, anchor in Kangaroo.
U and V are lines in datatree, there will be used as spring in Kangaroo, U above
This script could be used to draw sort of roads, like in here https://codequotidien.wordpress.com/2013/03/22/hemfunction/
But the primary purpose is to do that.
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- nickname is rather the best approach - and not on active group, but that's irrelevant anyway).
Step back (assuming that you are talking about the "Tens_from_random_blah_blah" definition):
1. Engineering is the art of demystifying (or we are promising that anyway, he he). This means that you start defining (better: outlining) some topology for things based on some "generic" rules (like the ones applied for the masts,cables,cones etc etc). These things are kept in some kind of structure (Lists, DataTrees etc). Things are few in 99.99999% of cases (i.e. : even the biggest membrane "module" has, say, 20-50 masts per "module").
2. Then ... handling things "individually" (mostly modifying) becomes the most critical part. See this (an x "possible" solution by combining a myriad of "options" : a no cones membrane solution, in plain English):
3. But the above is impossible (for more than obvious reasons). You should deploy masts in some high/low sequence in order to achieve some meaningful convex/concave formation that could work.
4. This "works" : 5. This doesn't:
6. This works partially (the formation at the back is "flat" == undo able):
7. This is utterly kitsch (and faulty as the case6 - the back portion):
So it's quite obvious that without a (quite complex) capability to individually control things (in this occasion : mast heights) the whole definition is a waste of computer time. Additionally the more the solution is "demystified" (some curve is defined, some random points are created, some masts are in place, some cables appear etc etc) the more additional constrains are required in order to "narrow" the possibilities (In plain English : sliders should control other sliders as regards their min/max values, true/false, you/me etc etc).
Remember that we are talking about ONE (mast height) out of a myriad things that you should control "manually" (it's utterly pointless to mastermind some kind of "generic" rules - or use naive attractors etc etc) .You'll see the difference when I'll completely reform the definition by adding individual control upon anything.
PS: what about the blocks? (the real life stuff that actually make any solution possible). Can you imagine a 2nd set of "restrictions" imposed by "a child to his parent"? (Assembly/Component modeling , that is).
more soon
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uick answers. Below you will find some suggestions, but don't think of them as rules and especially don't think of them as guarantees.
1. Choose a descriptive title for your post
Don't call your question "Help!" or "I have a problem" or "Deadline tonight!", but actually describe the problem you are having.
2. Be succinct but clear in your wording
People need to know some details about your problem in order to understand what sort of answers would satisfy you, but nobody cares about how angry your boss or how bad your teacher or how tight your deadline is. Talk about the problem and only the problem. If you don't speak English well, you should probably post in your native language as well as providing a Google Translation of your question.
3. Attach minimal versions of all the relevant files
If you have a GH/GHX file you have a question about, attach it to the post. Don't expect that people will recreate a file based on a screen-shot because that's a lot of pointless work. It's also a good idea to remove everything non-essential from a GH file. You can use the 'Internalise Data' menu option to cut everything to the left of a parameter:
If you're importing curves or Breps or meshes from Rhino, you can also internalise them so you won't have to post a 3DM file as well as a GH file. If you do attach large files, consider zipping them first. Do not use RAR, Ning doesn't handle it.
It is especially a good idea to post files that don't require any non-standard components if at all possible. Not everyone has Kangaroo or Hoopsnake or Geco installed so if your file relies on those components, it might not open correctly elsewhere.
4. Include a detailed image of the GH file if it makes sense
If your question is about a specific (group of) components, consider adding a screenshot of the file in the text of the post. You can use the Ctrl+Shift+Q feature in Grasshopper to quickly create nice screenshots with focus rectangles such as this:
5. Include links to online resources if possible
If you have a question about Schwarz Minimal surfaces, please link to a website which talks about these.
6. Create new topics rather than continuing old ones
It's usually better to start a fresh question, even if there's already a discussion that kinda sorta tangentially touches upon the same issue. Please link to that discussion, but start anew.
7. This is not a 'do my work for me' group
Many of us like to help, but it's good to see effort on our part being matched by effort on your part. Questions in the form of 'I need to do X but cannot be bothered to try and learn the software' will (and should) go unanswered.
7b. Similarly, questions in the form of 'How do I quickly recreate this facade that took a team of skilled professionals four months to figure out?' have a very low success rate.
--
David Rutten
Lead Grasshopper Development
Robert McNeel & Associates…
Added by David Rutten at 12:58pm on October 1, 2013
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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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he example file to this file so you can give it a try with any version of Honeybee that you're already using. The only requirement is to have OpenStudio installed as the component is using OpenStudio libraries to parse gbXML files. If you're using the latest version available on github the component is also available under WIP tab.
Why?
The main purpose of developing this component is to save time and effort for importing Revit models for energy and daylight analysis. It bothers me to see a lot of smart people spend a lot of time to just come up with solutions just to get the geometry from Revit to Honeybee for analysis. This component is not solving all the issue but is a first step forward. In an ideal world, the future version of Honeybee, which works both under DynamoBIM and Grasshopper should address this issue but that can take some time to be fully ready!
How?
To use this component you need to Export your Revit model as gbXML and then use the file path to load the file into Grasshopper. There are several resources available online on how to prepare the analytical model in Revit and export the gbXML file. Here is an image for importing the Revit 2017 sample model using the default settings. As you can see the model will be just as good as what your original gbXML file from Revit is.
What can be improved?
Well, there are several items that can be improved and they are mostly not on us. To get it started I add what I think are the 3 main shortcomings and my thoughts on how they can be addressed in the future. Feel free to add what you think needs to be added to this list in the comments section.
1. Revit analytical models and as the results gbXML files, by design, are not intended to be clean. Watch this presentation from the Autodesk University to see the logic behind this approach which in short is it doesn't matter for a large scale early stage energy model. Well, This will be quite a problem for studies that you can do with Honeybee. Included but not limited to daylight and comfort analysis.
The best solution that I can think of, until Autodesk fixes their exporter, is to use Revit Rooms and Spaces and generate a clean model from the scratch. We have already tried this approach in Revit but since the Revit API doesn't provide access to Room openings we had a very hard time to get it to work.
That's why that I opened an idea on Revit ideas to get over this issue. With your support we already have 81 votes, but it hasn't been enough to make them to consider the idea for an official review. If you haven't voted already and you think this will be a helpful feature take a moment and vote so we can have it implemented at some point in the future.
2. There is no way (that I know) to export only part of the model. The way export gbXML is set up in Revit is to export the whole model once together. As a result, if you have a huge model with 100 rooms and you want to get one of the rooms into Honeybee using this component you have to export the whole model, which can take some time, and then import them all back into Grasshopper. To partially address this issue I added an input to the component that allows you input a list of names for rooms that you're interested to be loaded into Grasshopper. You can use the name of the room/space in Revit as an input for the component.
3. The component doesn't import adjacencies, loads, schedules and HVAC systems. I wasn't able to export a gbXML file from Revit with any of this data except for the adjacency, but even if you can do that, the component currently can only import geometries and constructions. I hope we get access to 1 and so we don't have to use the xml file approach at all, but if that takes a very long time then we will add these features to the component.
Happy 2017!
Mostapha…
t defined from the discussion of radiation exchange between urban surfaces and the sky in urban heat island research (See Oke's literature list below). It will be affected by the proportion of sky visible from a given calculation point on a surface (vertical or horizontal) as a result of the obstruction of urban geometry, but it is not entirely associated with the solid angle subtended by the visible sky patch/patches.
So, I think using "geometry way" to approximate Sky View Factor is not correct. Sky View Factor calculation shall be based on the first principle defining the concept: radiation exchange between urban surface and sky hemisphere:
(image extracted from Johnson, G. T., & Watson, 1984)
Therefore, I always refer to the following "theoretical" Sky View Factors calculated at the centre of an infinitely long street canyon with different Height-to-width ratios in Oke's original paper (1981) as the ultimate benchmark to validate different methods to calculate SVF:
So, I agree with Compagnon (2004) on the method he used to calculate SVF: a simple radiation (or illuminance) simulation using a uniform sky.
The following images are the results of the workflow I built in the procedural modeling software Houdini (using its python library) according to this principle by calling Radiance to do the simulation and calculation, and the SVF values calculated for different canyon H/W ratios (shown at the bottom of each image) are very close to the values shown in Oke's paper.
H/W=0.25, SVF=0.895
H/W=1, SVF=0.447
H/W=2, SVF=0.246
It seems that the Sky View Factor calculated from the viewAnalysis component in Ladybug is not aligned with Oke's result for a given H/W ration: (GH file attached)
According to the definition shown in this component, I assume the value calculated is the percentage of visible sky which is a geometric calculation (shooting evenly distributed rays from sensor point to the sky and calculate the ratio of rays not blocked by urban geometry?), i.e solid angle subtended by visible sky patches, and it is not aligned with the original radiation exchange definition of Sky View Factor.
I'd suggest to call this geometrically calculated ratio of visible sky "Sky Exposure Factor" which is "true" to its definition and way of calculation (see the paper on Sky Exposure Factor below) so as to avoid confusion with "The Sky View Factor based on radiation exchange" as discussed in urban climate literature.
Appreciate your comments and advice!
References:
SVF: definition based on first principle
Oke, T. R. (1981). Canyon geometry and the nocturnal urban heat island: comparison of scale model and field observations. Journal of Climatology, 1(3), 237-254.
Oke, T. R. (1987). Boundary layer climates (2nd ed.). London ; New York: Methuen.
Johnson, G. T., & Watson, I. D. (1984). The Determination of View-Factors in Urban Canyons. Journal of American Meteorological Society, 23, 329-335.
Watson, I. D., & Johnson, G. T. (1987). Graphical estimation of sky view-factors in urban environments. INTERNATIONAL JOURNAL OF CLIMATOLOGY, 7(2), 193-197. doi: 10.1002/joc.3370070210
Papers on SVF calculation:
Brown, M. J., Grimmond, S., & Ratti, C. (2001). Comparison of Methodologies for Computing Sky View Factor in Urban Environments. Los Alamos, New Mexico, USA: Los Alamos National Laboratory.
SVF calculation based on first principle:
Compagnon, R. (2004). Solar and daylight availability in the urban fabric. Energy and Buildings, 36(4), 321-328.
paper on Sky Exposure Factor:
Zhang, J., Heng, C. K., Malone-Lee, L. C., Hii, D. J. C., Janssen, P., Leung, K. S., & Tan, B. K. (2012). Evaluating environmental implications of density: A comparative case study on the relationship between density, urban block typology and sky exposure. Automation in Construction, 22, 90-101. doi: 10.1016/j.autcon.2011.06.011
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ni-corso introduttivo di Rhino e Grasshoper
Il corso non spiega una stampante 3D in particolare (quelle presenti sono state realizzate dai docenti) ma si rivolge a chiunque abbia la necessità di progettare un oggetto in 3D tra cui artigiani, studenti, ingegneri, progettisti spiegando pregi e difetti di tutte le stampanti.
Dalle 14.00 alle 16.00 Andrea Bruni e Valerio Monticelli di Studio MP affronteranno i temi:
1) Introduzione al mondo della stampa 3D
2) Il primo passo è creare un modello 3D - Introduzione pratica alla modellazione 3D con gli strumenti offerti dal software Rhinoceros
3) Preparazione e slicing attraverso Cura dei modelli per ottenere i risultati desiderati - ogni singola geometria è un mondo a sé. Non faremo qualcosa per te ma ti spiegheremo come farlo da solo.
Dalle 16.00 alle 18.00 Antonino Marsala di Mandarino Blu terrà un mini-workshop di introduzione aGrasshopper e la scomposizione di un pattern matematici secondo il processo di reverse engineering.
- Introduzione alla modellazione parametrica/generativa attraverso l'uso di Grasshopper- Il fiore della vita: significato simbolico e matematico- Scomposizione geometrica e analitica- Creazione del pattern attraverso la geometria generativa- Applicazioni pratiche
Biglietto 10,00 €
Biglietti disponibili al seguente link…