nter the programming world and tinker more complex, interactive solutions. We will also explore advanced programming paradigms. There is no class official programming language, as both C# and Vb.Net are possible on the participant’s side, and all examples will be provided in both C# and Vb.Net. Additionally, we will see how to get started writing full .Net plug-ins. Finally, we will have time to explore user’s own proposals on the third day.
Day 1 Morning: programming introduction in .Net
• The Grasshopper scripting components. Choosing a .Net language. Language developments
• Variables declaration, assignment and utilization. Operators. Methods [functions]. Calls
• Classes: declaration and instancing. Constructors. Importing a namespace. On3dPoints, OnLines
• Arrays declaration and usage. Lists. Adding to arrays and lists, advantages and opportunities.
Afternoon: patterns
• About OOP (object oriented programming) as opposed to procedural programming. Discussion
• Example of OOP good code reuse: sorting points by coordinates using the .Net SDK classes
• Lists as input parameters. Trees as input parameters. Usage and limitations
• Finding resources: on the net with website that can help getting started and troubleshoot. And books
Day 2 Morning: extending Grasshopper functionality with our definitions
• Store data between updates. The use of fields [globals, or static locals]
• Examples on how to use stored data between updates: a simple agents simulation
• Baking geometry with scripting directly into the Rhino document. Baking with names
• Passing custom types from a scripted component to another one. Our own code reusability
• Rendering an animation from Grasshopper. How to get started and final results
Afternoon: customizing our tools
• Our Rhino plug-in with Visual Studio C# [Vb.Net] Express Edition & wizard. Parametric mesher
• Writing a custom Grasshopper component: hacking an exporter for our data to Excel
Day 3 All day: personal project
• Rehearsal on any example from the first two days. A project that you want to start on your own, being it a Rhinoceros plug-in, a Grasshopper assembly or a script. Example might be to send data through network with UDP to Processing
MINIMUM REQUIREMENTS
A good foundation of Grasshopper visual programming is mandatory. You will need a level which corresponds to the Grasshopper 101 course outline. Examples of things that will not be covered in this course are: sorting document spheres by diameter, paneling of a surface with grasshopper components. You are expected to already know these from the Grasshopper course.…
to enter the programming world and tinker more complex, interactive solutions. We will also explore advanced programming paradigms. There is no class official programming language, as both C# and Vb.Net are possible on the participant’s side, and all examples will be provided in both C# and Vb.Net. Additionally, we will see how to get started writing full .Net plug-ins. Finally, we will have time to explore user’s own proposals on the third day.
Day 1 Morning: programming introduction in .Net • The Grasshopper scripting components. Choosing a .Net language. Language developments • Variables declaration, assignment and utilization. Operators. Methods [functions]. Calls • Classes: declaration and instancing. Constructors. Importing a namespace. Point3d, Lines • Arrays declaration and usage. Lists. Adding to arrays and lists, advantages and opportunities. Afternoon: patterns • About OOP (object oriented programming) as opposed to procedural programming. Discussion • Example of OOP good code reuse: sorting points by coordinates using the .Net SDK classes • Lists as input parameters. Trees as input parameters. Usage and limitations • Finding resources: on the net with website that can help getting started and troubleshoot. And books Day 2 Morning: extending Grasshopper functionality with our definitions • Store data between updates. The use of fields [globals, or static locals] • Examples on how to use stored data between updates: a simple agents simulation • Baking geometry with scripting directly into the Rhino document. Baking with names • Passing custom types from a scripted component to another one. Our own code reusability • Rendering an animation from Grasshopper. How to get started and final results Afternoon: customizing our tools • Our Rhino plug-in with Visual Studio C# [Vb.Net] Express Edition & wizard. Parametric mesher • Writing a custom Grasshopper component: hacking an exporter for our data to Excel Day 3 All day: personal project • Rehearsal on any example from the first two days. A project that you want to start on your own, being it a Rhinoceros plug-in, a Grasshopper assembly or a script. Example might be to send data through network with UDP to Processing MINIMUM REQUIREMENTS A good foundation of Grasshopper visual programming is mandatory. You will need a level which corresponds to the Grasshopper 101 course outline. Examples of things that will not be covered in this course are: sorting document spheres by diameter, paneling of a surface with grasshopper components. You are expected to already know these from the Grasshopper course.…
rectly except for the first material in a series. See attached image... Here is my code:
Private Sub RunScript(ByVal M As Object, ByVal C As Color, ByRef AddName As Object, ByRef AddMat As Object, ByRef AddBool As Object, ByRef baseName As Object, ByRef newMatName As Object)
Dim z As String = "newMatName" Dim y As String = "BaseName" Dim x As Integer = 0 Dim nRestore As String Dim mTemp As Rhino.DocObjects.Material
mTemp = CType(M, Rhino.DocObjects.Material) y = mTemp.Name Dim nTemp As String
If mTemp.Name.Contains("_MOD_R") = False Then
nRestore = mTemp.Name nTemp = mTemp.Name & "_MOD_R" & C.R & "_G" & C.G & "_B" & C.B mTemp.Name = nTemp z = nTemp mTemp.DiffuseColor = C
If Doc.Materials.Find(nTemp, True) < 0 Then
Doc.Materials.Add(mTemp) x = x + 1 AddName = nTemp AddMat = mTemp
End If
mTemp.Name = nRestore
End If
newMatName = z
AddBool = x BaseName = y
End Sub
1) I have checked that all of the materials I am calling by name exist in the document and that data matching is correct. There doesn't seem to be anything special about the offending material except that it is always the first material that was added to the document by my script.
2) The main thing I was missing in the previous script was the "doc.Materials.Add()" -- how on earth should I have known that existed? Even a search for "doc.Materials" in the Rhinocommon SDK doesn't turn that up. I'm having a very hard time using the SDK to my advantage, it seems not to correlate to the actual code I need to write.
2b) Perfect example... now I am trying to rewrite my other component (which exposes all of the document materials) to set a few objects manually in Rhino with the Materials I want to use as templates. Now I am trying to find out how to access the material assigned to an object. Seems easy, but it's clearly not a Property, and I can't find an appropriate Method in either the Objects or Materials classes.
3) One of my problems originally, when feeding the component one material and multiple colors, was that the nTemp variable was not resetting properly for the second color. Same thing if I duplicated the material to match the list of colors. It would create a material on the first pass but concatenate "_MOD_R_G_B" in each subsequent pass and be caught by my String checker. Why is that? I thought that the nTemp Name variable would be reset in each pass by the line "mTemp = CType(M, Rhino.DocObjects.Material)" and "nTemp = mTemp.Name" combination.
Does the mTemp material somehow carry over its properties in each successive pass? That's why I added the nRestore to be sure each pass reset the name back to the original.
Still, I wonder if there is some problem with the way I am conceptualizing this that is causing the first material to be the same as the input material.
Thanks for your help on this...
Cheers,
Marc…
Python and install it and it should work fine.
2. You still see the image above in case 1 however you have GHPython already installed. What about that?
In this case probably the GHA component is blocked. Find GHPython.GHA on your system (usually at: C:\Users\%username%\AppData\Roaming\Grasshopper\Libraries) . Right click, go to properties and select unblock.
To make sure that GHPython is working fine on your system open the attachment file (testGHPython.gh). You should see something similar to the image below on your screen when you open the file:
If you see the something similar you should be fine to go! Try to open one of the example files.
3. You have Ladybug running but in some of the case the output is missing. You see something similar to this:
or this
This one is because you are using old version of GHPython. Close the file without saving. Download the new version and install it and re-open the file. It should work fine now.
Hope it helps,
Mostapha
…
the mesh into long strips 1 quad wide.
*I did make an alternative icon for this, but opted for the tamer one in the end ;)
The Unroller component goes along the strip face by face, rotating it into a single plane.
Note that this component will still give a result even if you supply it with non planar quads - it will just fold them along a diagonal. However, if the faces are significantly non-planar, then it won't work as well for fabricating from a smooth strip of sheet material, so it is better to try and make sure your planarizing in the relaxation part is working well.
The Unroller component also has a T input which allows you to unroll only part of the mesh at a time. This is mainly for animation purposes, and most of the time you will probably just want to leave it set at 1.
At the moment the unroller is limited to working with open strips, so if your strip forms a closed loop, you will have to split it first. Later releases should include an automatic 'loop snipper'.
The final part of the definition then takes all these strips, orients them into the XY plane, and does some very basic layout.
It's then up to you to label, add tabs, nest, laser cut and assemble!
Because of the subdivision, each strip should have an even number of quads, which can also be useful for generating interlocking tabs by offsetting alternate groups of edges. I'll try and post an example of this soon.
I hope this is helpful. It was my intention when making this that it could be a relatively quick and easy way of making smooth curved structures out of sheet material, (I'm thinking card, polypropylene, metal, thin plywood...) with a lot less fixing/connecting work than doing a similar shape with individual panels.
Thanks to all the participants in these long-running threads:
http://www.grasshopper3d.com/forum/topics/how-to-create-nodesbone
http://www.grasshopper3d.com/forum/topics/skeletal-mesh*
which inspired this work, especially some of the comments by Ivan Kiryakov, Wiktor Kidziak, Giulio Piacentino, Andrew Haas and Mårten Nettelbladt.
*note also that the meshes generated using this definition can be used for developable strips, because they have the even-valence property.
I was also inspired by these papers:
http://www.cs.jhu.edu/~misha/Fall09/Liu06.pdf
http://www.geometrie.tugraz.at/wallner/strip.pdf…
lName, signalValue, operationMode):
sigV=signalValue
if sys.version_info[0] == 3:
if type(signalName) is str:
signalName=signalName.encode('utf-8')
if type(signalValue) is bytearray:
sigV = (ct.c_ubyte*len(signalValue))(*signalValue)
if type(signalValue) is str:
signalValue=signalValue.encode('utf-8')
sigV = (ct.c_ubyte*len(signalValue))(*signalValue)
else:
if type(signalValue) is bytearray:
sigV = (ct.c_ubyte*len(signalValue))(*signalValue)
if type(signalValue) is str:
signalValue=bytearray(signalValue)#<========This is line 1052
sigV = (ct.c_ubyte*len(signalValue))(*signalValue)
sigV=ct.cast(sigV,ct.POINTER(ct.c_ubyte)) # IronPython needs this
return c_WriteStringStream(clientID, signalName, sigV, len(signalValue), operationMode)
It displays the following error:
Program started
Connected to remote API server
Runtime error (TypeErrorException): unicode argument without an encoding
Traceback:
line 1052, in simxWriteStringStream, "C:\Program Files (x86)\V-REP3\V-REP_PRO_EDU\programming\remoteApiBindings\python\python\vrep.py"
line 70, in script
Any hint?…
d simulate the bending process of a flat stell sheet in order to get the same shape. This can be really interesting so we can evaluate the material beheaviour, the deformation on the cross section a
nd explore big deformations in mecanics analysis of materials.
I am not a mecanical engineer nor a civil engineer, I´m an Architect and my interest is the construcction method and extracting the necesary information to consider fabricating the project.
I´m having conceptual challengings on the methodology for this simulation, so I will post a small overview of what I`ve done.
1.- Understanding the Geometry.
This is a sclupture by the Venezuelan/Hungarian/German artist Zoltan Kunckel (KuZo).
The shape is achieved bending a pre water cut square sheet of stainless steel. After bended manually, the different lashes are pulled on the opposite direction. New curvatures are produced after all is deployed.
2.- Reproducing the Shape digitally.
Using Karamba I built a definition to reproduce the produced by physical stress. This model served to find deformations that occur when a set of loads are applied to a mesh. Following this process will allow us to find a coherent and more natural cross section so then we could re-shape simulating the bending process of a piece of ductile material.
3.- Discretizing curve
Reducing the model to its simplest element is a key aspect of finite nonlinear analysis. Once our shape is already defined we can divide its principal characteristic of its principal given curve.
At this point I have already found the desired curve.
I Think the better strategy to simulate bending the steel sheet into this shape, is rationalize the curve and divide it finding the tangents one of the curve that compose this sort of parabola. bur i don`t know how to parametrize that in GH.
Please. If someone have a better Idea about this process I`ll glad to read sugestions.
Tomás Mena
…
to enter the programming world and tinker more complex, interactive solutions. We will also explore advanced programming paradigms. There is no class official programming language, as both C# and Vb.Net are possible on the participant’s side, and all examples will be provided in both C# and Vb.Net. Additionally, we will see how to get started writing full .Net plug-ins. Finally, we will have time to explore user’s own proposals on the third day.
Day 1 Morning: programming introduction in .Net
• The Grasshopper scripting components. Choosing a .Net language. Language developments
• Variables declaration, assignment and utilization. Operators. Methods [functions]. Calls
• Classes: declaration and instancing. Constructors. Importing a namespace. Point3d, Lines
• Arrays declaration and usage. Lists. Adding to arrays and lists, advantages and opportunities.
Afternoon: patterns
• About OOP (object oriented programming) as opposed to procedural programming. Discussion
• Example of OOP good code reuse: sorting points by coordinates using the .Net SDK classes
• Lists as input parameters. Trees as input parameters. Usage and limitations
• Finding resources: on the net with website that can help getting started and troubleshoot. And books
Day 2 Morning: extending Grasshopper functionality with our definitions
• Store data between updates. The use of fields [globals, or static locals]
• Examples on how to use stored data between updates: a simple agents simulation
• Baking geometry with scripting directly into the Rhino document. Baking with names
• Passing custom types from a scripted component to another one. Our own code reusability
• Rendering an animation from Grasshopper. How to get started and final results
Afternoon: customizing our tools
• Our Rhino plug-in with Visual Studio C# [Vb.Net] Express Edition & wizard. Parametric mesher
• Writing a custom Grasshopper component: hacking an exporter for our data to Excel
Day 3 All day: personal project
• Rehearsal on any example from the first two days. A project that you want to start on your own, being it a Rhinoceros plug-in, a Grasshopper assembly or a script. Example might be to send data through network with UDP to Processing
MINIMUM REQUIREMENTS
A good foundation of Grasshopper visual programming is mandatory. You will need a level which corresponds to the Grasshopper 101 course outline. Examples of things that will not be covered in this course are: sorting document spheres by diameter, paneling of a surface with grasshopper components. You are expected to already know these from the Grasshopper course.…
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/
…
nts for Ladybug too. They are based on PVWatts v1 online calculator, supporting crystalline silicon fixed tilt photovoltaics.
You can download them from here, or use the Update Ladbybug component instead. If you take the first option, after downloading check if .ghuser files are blocked (right click -> "Properties" and select "Unblock").
You can download the example files from here.
Video tutorials will follow in the coming period.
In the very essence these components help you answer the question: "How much energy can my roof, building facade, solar parking... generate if I would populate them with PV panels"?
They allow definition of different types of losses (snow, age, shading...) which may affect your PV system:
And can find its optimal tilt and orientation:
Or analyse its performance, energy value, consumption, emissions...
By Djordje Spasic and Jason Sensibaugh, with invaluable support of Dr. Frank Vignola, Dr. Jason M. Keith, Paul Gilman, Chris Mackey, Mostapha Sadeghipour Roudsari, Niraj Palsule, Joseph Cunningham and Christopher Weiss.
Thank you for reading, and hope you will enjoy using the components!
EDIT: From march 27 2017, Ladybug Photovoltaics components support thin-film modules as well.
References:
1) System losses:
PVWatts v5 Manual, Dobos, NREL, 2014
2) Sun postion equations by Michalsky (1988):
SAM Photovoltaic Model Technical Reference, Gilman, NREL, 2014
edited by Jason Sensibaugh
3) Angle of incidence for fixed arrays:
PVWatts Version 1 Technical Reference, Dobos, NREL, 2013
4) Plane-of-Array diffuse irradiance by Perez 1990 algorithm:
PVPMC Sandia National Laboratories
SAM Photovoltaic Model Technical Reference, Gilman, NREL, 2014
5) Sandia PV Array Performance Module Cover:
PVWatts Version 1 Technical Reference, Dobos, NREL, 2013
6) Sandia Thermal Model, Module Temperature and Cell Temperature Models:
Photovoltaic Array Performance Model, King, Boys, Kratochvill, Sandia National Laboratories, 2004
7) CEC Module Model: Maximum power voltage and Maximum power current from:
Exact analytical solutions of the parameters of real solar cells using Lambert W-function, Jain, Kapoor, Solar Energy Materials and Solar Cells, V81 2004, P269–277
8) PVFORM version 3.3 adapted Module and Inverter Models:
PVWatts Version 1 Technical Reference, Dobos, NREL, 2013
9) Sunpath diagram shading:
Using sun path charts to estimate the effects of shading on PV arrays, Frank Vignola, University of Oregon, 2004
Instruction manual for the Solar Pathfinder, Solar Pathfinder TM, 2008
10) Tilt and orientation factor:
Application for Purchased Systems Oregon Department of Energy
solmetric.com
11) Photovoltaics performance metrics:
Solar PV system performance assessment guideline, Honda, Lechner, Raju, Tolich, Mokri, San Jose state university, 2012
CACHE Modules on Energy in the Curriculum Solar Energy, Keith, Palsule, Mississippi State University
Inventory of Carbon & Energy (ICE) Version 2.0, Hammond, Jones, SERT University of Bath, 2011
The Energy Return on Energy Investment (EROI) of Photovoltaics: Methodology and Comparisons with Fossil Fuel Life Cycles, Raugei, Fullana-i-Palmer, Fthenakis, Elsevier Vol 45, Jun 2012
12) Calculating albedo: Metenorm 6 Handbook part II: Theory, Meteotest 2007
13) Magnetic declination:
Geomag 0.9.2015, Christopher Weiss…