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
: ----------------------------------------------------------------------------------------------
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
----------------------------------------------------------------------------------------------…
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 !
…
guages I'd recommend all use the RhinoCommon SDK and thus all have access to the same functionality.
How long would it take me to understand and write my own code?
If you already know how to program, it probably won't take too long. If you're past the hurdle of what it means to declare and assign variables, how conditionals and loops work and what scope is, you've already rounded the hardest corner.
Is it even worth it?
That really depends. "Learn programming" is clearly not blanket good advice. Most people out there do not have to learn programming to be happy with their lives and successful in their careers. For some people it can make a small difference, and for a few people it can make a huge difference. If you feel you're in the 'some' category then this is indeed a question you have to answer. Note that the investment for learning programming is a continuous process. Unless you keep up your skills and learn about new stuff that becomes available, you'll lose the ability to write successful code over time.
Where do I start?
Step 1 is to answer the previous question. It is unlikely that anyone besides yourself can answer it, but you can start by making a list of things you do manually now that may be programmable. Then make a list of the things you are unable to do now but which you might be able to do with programming. If while looking at these lists your reaction is: "meh", the answer is probably no.
Step 2 is to pick a language. This is again a very personal thing; there's no wrong answer, because there's no right answer.
Step 3 is to start learning this language. My experience is that the best way to learn a programming language is to try and solve a real problem that you understand very well. If the problem statement is nebulous or poorly understood, you'll be learning two things and that's a recipe for unnecessary frustration.
Here are my thoughts on language:
Python: I don't use Python myself, I can sort of read it while moving my lips. I don't particularly like Python though. The indentation sensitiveness stresses me out, and I find the lack of type-safety disturbing. However it is a good language for mathematical/scientific programs. There are lots of additional code libraries you can easily import that will ease the development of mathematically intense algorithms.
C#: I like C# very much, but it does suffer from geekerosis. A lot of the keywords used in the language are not self-explanatory (abstract, sealed, virtual). For me this is no longer a problem as I've memorised what they all mean. C# is designed to be an efficient language to write, rather than an easy one to learn.
The great thing about C# though is that there's a huge amount of material out there for learning it. It is one of the most popular, mature and modern languages you can hope to pick.
VB: I learned VBScript as my first language, and then moved on to VB5, VB6 and VB.NET. It is somewhat more friendly than C#, and functionally it is almost identical. The switch from VB to C# is reasonably low-threshold and there are excellent tools for translating VB code to C# and vice versa.
Since you already know some Python, it probably makes the most sense to continue on that path. If you want to switch, C# is more like Python than VB, so C# would be my next suggestion.
As for where to get information... you have 4 major options when developing code for Rhino.
If it's a question about the language itself, StackOverflow is a great resource. It can be a pretty hostile place for beginner questions, but I find that mostly the questions I'm asking have been asked already and the answers on SO tend to be good. In fact usually when I google my questions, the first few hits are always SO posts.
If it's a question about the Rhino SDK or Grasshopper, you can ask it either on the GH forums (where we are now), or on Discourse. We're not as quick on the draw as SO, but we do know about Rhino.
If you're looking for a basic explanation of what a keyword or a type is for, perhaps with an example, MSDN is the best first choice. In fact if you google the name a of a .NET type, the first hit is almost always an MSDN page.…
Added by David Rutten at 2:03pm on December 3, 2014
umbrella of Urban Heat Island (UHI) and I am going to try to separate them out in order to give you a sense of the current capabilities in LB+HB.
1) UHI as defined as a recorded elevated air temperature in an urban area:
If you have access to epw files for both an urban area and a rural area, you can use Ladybug to visualize and deeply explore the differences between the two weather files. Ladybug is primarily a tool for weather file visualization and analysis and it can be very helpful for understanding the consequences of UHI on strategies for buildings or on comfort. This said, if you do not have both rural and urban recorded weather data or you want to generate your own weather files based on criteria about urban areas (as it sounds like you want to do), this definition might not be so helpful.
2) UHI defined by air elevated air temperature but viewed as a computer model-able phenomenon resulting primarily from urban canyon geometry, building materials, and (to a lesser degree) anthropogenic heat:
This definition seems to fit more with they type of thing that you are looking for but it is unfortunately very difficult and computationally intensive such that we do not currently have anything within Ladybug to do this right now. I can say that the state-of-the art for this type of modeling is an application called Town Energy Budget (TEB) and this is what all of the advanced UHI researches that I know use (http://www.cnrm.meteo.fr/surfex/spip.php?article7). Unfortunately for those trying to use it in professional practice, it can take a while to get comfortable with it and it currently runs exclusively on Linux (this does mean that it is open source, though, and that you can really get deep into the assumptions of the model). A couple years ago, a peer of mine translated almost all of TEB into Matlab language making it possible to run it on Windows if you have Matlab. He wrapped everything together into a tool called the Urban Weather Generator (UWG), which can take an epw file of a rural area and warp it to an urban area based on inputs that you give of building height, materials, vegetation, anthropogenic heat, etc. I would recommend looking into this for your project, although, bear in mind that is it not open source like the original TEB tool and that you may need to get a (very expensive) copy of MATLAB (http://urbanmicroclimate.scripts.mit.edu/uwg.php).
3) UHI as defined by a thermal satellite image of an urban area depicting an elevated average radiant environment that reaches a maximum a the city center and changes by land use:
This is the definition of UHI that I am most familiar with and was the basis of much of my past research. I feel that it is also a definition of UHI that is a bit more in line with where a lot of contemporary UHI research is headed, which is away from the notion of UHI as a macro-scale meteorological phenomena that is averaged as an air temperature over a huge area towards one that accepts that different land uses have different microclimates and (importantly) different radiant environments. While the air temperature difference between urban and rural areas usually does not change more than 1-4 C, the radiant environment can be very different (on the order of 10-15 C differences). The best way to understand UHI in this context is with Thermal satellite images, for which there is ha huge database of publicly available data on NASA's glovis website (http://glovis.usgs.gov/) or their ECHO website (http://reverb.echo.nasa.gov/reverb/#utf8=%E2%9C%93&spatial_map=satellite&spatial_type=rectangle). I tend to use thermal data from LANDSAT 5-8 and ASTER satellites in my research. Unfortunately, there is a lot f bad data with a lot of cloud cover mixed in with the really good stuff and it can take some time to find good images. Also, there aren't too many programs that read the GeoTiff file format that you download the data as. I know that ArcGIS will read it, a program called ENVI will read it (I think that the open source QGIS can also red it). I have plans to write a set of components to bring this type of data into Rhino and GH (I may get to it a few months down the line).
4) UHI as a computer model-able notion of "Urban Microclimate" with consideration of local differences and the local radiant environment:
This is where a lot of my research has lead and, thankfully, is an area that Honeybee can help you out a lot with. EnergyPlus simulations can output information on outside building surface temperatures and these can be very helpful in helping get a sense of the radiant environment around individual buildings. Right now, I am focusing just on using this data to fully model the indoor environments of buildings as you see in this video:
https://www.youtube.com/watch?v=fNylb42FPIc&list=UUc6HWbF4UtdKdjbZ2tvwiCQ
I have plans to move this methodology to the outdoors once I complete this initial application to the indoors. For now, you can use the "Surface result reader" and the "color surfaces based on EP result" components to get a sense of variation in the outside temperature of your buildings.
I hope that this helped,
-Chris
…
l coarse mesh
Subdividing this mesh into strips of thin quads
Relaxing/Planarizing this mesh
Splitting and Unrolling
In this post I deal with the first 2 of these stages.
You can download the example definition here:
developable_strips_tutorial.gh
Drawing the initial mesh
To begin with we need a simple quad mesh. This can be modelled manually in Rhino, and only needs to use enough quads to give the topology and very rough form. No need to worry too much about the exact geometry or dimensions at this point, as we will refine and alter it as we go.
One very important thing that we do need to bear in mind though is that all internal vertices must have even valence (I covered this a bit in the earlier post here).
So for example, this is bad:
(because the highlighted vertex is surrounded by 5 faces)
While this is good (and can still be relaxed to the same shape):
(the top and bottom vertices have valence 8, and the vertices between the arms have valence 4)
With a little practice it should be possible to convert any mesh into one that meets this condition.
The reasons why we need this condition should become more clear in the later steps.
First subdivision
This is where we choose how many strips we want our final model to have, by applying a few rounds of subdivision using the Refine component (you could also use Weaverbird here):
Sorting the face directions
While quad meshes do not carry the same information about u/v directions as a NURBS surface, the individual faces do have a sort of direction given by their vertex ordering. However, these face directions are usually not consistently arranged, especially after subdivision.
The Kangaroo MeshDirection component attempts* to orient all the faces in a mesh so that they match with their neighbours.
For example, before sorting, if we draw a line from the midpoint of the first edge of each face to the midpt of its opposite edge, we might get something like this:
Whereas after sorting, we should get something like this:
*note that I say it attempts to orient the faces consistently. In some cases no valid solution exists, for instance if 3 or 5 faces meet around a vertex, hence the requirement mentioned at the start for even valence vertices.
Directional Subdivision
Now that we have consistent face directions across the mesh, we can apply further subdivision, but this time in one direction only. So we go from roughly square quads to thin rectangles. The idea is that as we apply higher levels of this directional subdivision, the final relaxed result goes towards something semi-discrete. A NURBS surface is fully continuous, and a mesh is fully discrete (made up of separate facets), while this strip model will be smooth in one direction and faceted in the other.
Go to part 2 for the next step of the process
…
y from the Rhino model and having the absorption coefficients of the materials that are entered into Pachyderm, why is it not possible to generate a reverberation time diagram, without the need to start any analysis?
MAPPING METHOD: When for example the mapping of the Strenght Index (G) is generated through the "create map" option, succesively I can´t generate any other energy criterion map, but I have to redo the simulation.
Is it a limitation of the software or am I wrong something?
MAPPING METHOD: I kindly wanted to ask what is the difference between minimum and detailed convergence and why the number of reflections order it takes into account for the simulation is not specified. The mapping method take care only of the Raytracing Method or the Image Source too?
MAPPING METHOD: Why is the mapping value that can be exported to Rhino not generated for all the calculation raster points, but maximal only for 100 values?
MAPPING METHOD: This method hasn't been implemented in Grasshopper yet, has it?
RAYTRACING METHOD (Pach:RT): I did a raytracing through the components of GH, using only the Pach_RT, and I had these curious results in terms of time:
RaysCount: 15.000, IS_Order:1 = 5min
RaysCount: 15.000, IS_Order:2 = 12min
RaysCount: 15.000, IS_Order:3 = 3min
RaysCount: 15.000, IS_Order:4 = 8min
RaysCount: 15.000, IS_Order:5 = 3min
Why a raytracing with only 2 order, is more and more extensive than the 3/4 and 5 order?
ANALYSIS RESULT: Would there be a way to export all the results of a simulation, as is done via Odeon, to a .txt list?
I apologize in advance for asking so many questions, I hope you can find the time to answer,
Yours sincerely from Müller-BBM…