: ----------------------------------------------------------------------------------------------
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
----------------------------------------------------------------------------------------------…
nside a script.
However, it should be noted that to do so introduces a significant amount of overhead, which may impact performance. This is because (to the best of my understanding) all the methods described below actually instantiate and execute a virtual Grasshopper document, with components and everything else. Whenever possible, it is advisable to simply call RhinoCommon functions - these are designed to be called in code and are more streamlined.
Python
Grasshopper's Python is unique among the scripting languages in that it has a "node-in-code" mechanism for this purpose in the form of the ghpythonlib library and its "components" class. Here is some example code:
from ghpythonlib import components as ghcomp import Rhino a = ghcomp.Circle(Rhino.Geometry.Plane.WorldXY,25.0) result = ghcomp.DeconstructBrep(b) faces = result[0] edges = result[1] vertices = result[2]
This code will call the "Circle" component with the world XY base plane and a radius of 25, and then call the "Deconstruct Brep" component on a brep (input to the script as "b").
The arguments passed to the function will correspond to the inputs of the component, and the function will return the output (the data itself in the case of a component with only one output, and a tuple of data in the case of multiple outputs, as in the second example above).
For more info on this technique, see this post by Steve Baer.
C#/VB.Net
James Ramsden has described a method for doing this in these two posts on his blog:
Run a Grasshopper Component from C# Code
Read and edit persistent data in Grasshopper components with C#
His examples are in C#, but everything he describes can also be done in VB.net with some syntax tweaks.
The core of his method is to programmatically instantiate a component, populate its inputs, and then create a virtual grasshopper document in which to execute the code. He then harvests the outputs and converts them back to simple data. Here is his example code for calling the "Circle by Normal and Radius" component:
var cs = new CurveComponents.Component_CircleCNR(); //add the circle centre (input 0) var pp = cs.Params.Input[0] as Grasshopper.Kernel.GH_PersistentGeometryParam<Grasshopper.Kernel.Types.GH_Point>; pp.PersistentData.ClearData(); pp.PersistentData.Append(new GH_Point(new Point3d(0, 0, 3))); //add the circle radius (input 2) var pn = cs.Params.Input[2] as Grasshopper.Kernel.GH_PersistentParam<Grasshopper.Kernel.Types.GH_Number>; pn.PersistentData.ClearData(); pn.PersistentData.Append(new GH_Number(y)); //y is another variable //run calculations cs.ExpireSolution(true); //add to a dummy document so we can read outputs var doc = new Grasshopper.Kernel.GH_Document(); doc.AddObject(cs, false); //read output circle cs.Params.Output[0].CollectData(); A = cs.Params.Output[0].VolatileData.get_Branch(0)[0]; //remove that component doc.RemoveObject(cs.Attributes, false);
Final notes
For a great many of the simple components, there are in fact methods in RhinoCommon that accomplish exactly the same thing. Note the complexity of the above code, and then look at the equivalent code using RhinoCommon methods:
Circle circle = new Circle(new Plane(origin, normal), radius);
In my experience it is preferable to just call or construct the methods you need using RhinoCommon rather than relying on trying to call components from inside your code.
Lastly, It is my understanding that this concept is central to David's thinking around GH2 - so that it in the next version it will be significantly more streamlined to switch between components and code representations. (I have no special knowledge of GH2 development - this is just what I have seen David say on the forums, and as usual any statements about future features are subject to change.)
Hope this is helpful!
…
rmation?" I know that this can already be accomplished using the brilliant Kangaroo plugin, but I wanted a simpler and faster (yet still accurate) single component that could replicate this unique curve using a variety of inputs: the length of the rod/wire, the width/distance between the endpoints, the height of the bend, and the tangent angle at the start. I also wanted make the unknowns (such as height if only length and width are known) easily accessible for plugging into additional components.
The resulting script, being an all-in-one solution, is somewhat unwieldy, but it could easily be broken down into smaller components (custom .gha's which I don't have the ability to code). If someone wants to tackle this, please do! I'm not an expert coder by any means, and as this was only my second time diving into Grasshopper scripting, if the script seems somewhat strange, that's probably why. I did try to comment the code pretty well though. Here's the full description:
--------------------------------------------------
DESCRIPTION: This beast creates the so-called 'elastica curve', the shape a long, thin rod or wire makes when it is bent elastically (i.e. not permanently). In this case, force is assumed to only be applied horizontally (which would be in line with the rod at rest) and both ends are assumed to be pinned or hinged meaning they are free to rotate (as opposed to clamped, when the end tangent angle is fixed, usually horizontally). An interesting finding is that it doesn't matter what the material or cross-sectional area is, as long as they're uniform along the entire length. Everything makes the same shape when bent as long as it doesn't cross the threshold from elastic to plastic (permanent) deformation (I don't bother to find that limit here, but can be found if the yield stress for a material is known).
Key to the formulas used in this script are elliptic integrals, specifically K(m), the complete elliptic integral of the first kind, and E(m), the complete elliptic integral of the second kind. There was a lot of confusion over the 'm' and 'k' parameters for these functions, as some people use them interchangeably, but they are not the same. m = k^2 (thus k = Sqrt(m)). I try to use the 'm' parameter exclusively to avoid this confusion. Note that there is a unique 'm' parameter for every configuration/shape of the elastica curve.
This script tries to find that unique 'm' parameter based on the inputs. The algorithm starts with a test version of m, evaluates an expression, say 2*E(m)/K(m)-1, then compares the result to what it should be (in this case, a known width/length ratio). Iterate until the correct m is found. Once we have m, we can then calculate all of the other unknowns, then find points that lie on that curve, then interpolate those points for the actual curve. You can also use Wolfram|Alpha as I did to find the m parameter based on the equations in this script (example here: http://tiny.cc/t4tpbx for when say width=45.2 and length=67.1).
Other notes:
* This script works with negative values for width, which will creat a self-intersecting curve (as it should). The curvature of the elastica starts to break down around m=0.95 (~154°), but this script will continue to work until M_MAX, m=0.993 (~169°). If you wish to ignore self-intersecting curves, set ignoreSelfIntersecting to True
* When the only known values are length and height, it is actually possible for certain ratios of height to length to have two valid m values (thus 2 possible widths and angles). This script will return them both.
* Only the first two valid parameters (of the required ones) will be used, meaning if all four are connected (length, width or a PtB, height, and angle), this script will only use length and width (or a PtB).
* Depending on the magnitude of your inputs (say if they're really small, like if length < 10), you might have to increase the constant ROUNDTO at the bottom
REFERENCES: {1} "The elastic rod" by M.E. Pacheco Q. & E. Pina, http://www.scielo.org.mx/pdf/rmfe/v53n2/v53n2a8.pdf {2} "An experiment in nonlinear beam theory" by A. Valiente, http://www.deepdyve.com/lp/doc/I3lwnxdfGz {3} "Snap buckling, writhing and Loop formation In twisted rods" by V.G.A. GOSS, http://myweb.lsbu.ac.uk/~gossga/thesisFinal.pdf {4} "Theory of Elastic Stability" by Stephen Timoshenko, http://www.scribd.com/doc/50402462/Timoshenko-Theory-of-Elastic-Stability (start on p. 76)
INPUT: PtA - First anchor point (required) PtB - Second anchor point (optional, though 2 out of the 4--length, width, height, angle--need to be specified) [note that PtB can be the same as PtA (meaning width would be zero)] [also note that if a different width is additionally specified that's not equal to the distance between PtA and PtB, then the end point will not equal PtB anymore] Pln - Plane of the bent rod/wire, which bends up in the +y direction. The line between PtA and PtB (if specified) must be parallel to the x-axis of this plane
** 2 of the following 4 need to be specified ** Len - Length of the rod/wire, which needs to be > 0 Wid - Width between the endpoints of the curve [note: if PtB is specified in addition, and distance between PtA and PtB <> width, the end point will be relocated Ht - Height of the bent rod/wire (when negative, curve will bend downward, relative to the input plane, instead) Ang - Inner departure angle or tangent angle (in radians) at the ends of the bent rod/wire. Set up so as width approaches length (thus height approaches zero), angle approaches zero
* Following variables only needed for optional calculating of bending force, not for shape of curve. E - Young's modulus (modulus of elasticity) in GPa (=N/m^2) (material-specific. for example, 7075 aluminum is roughly 71.7 GPa) I - Second moment of area (or area moment of inertia) in m^4 (cross-section-specific. for example, a hollow rod would have I = pi * (outer_diameter^4 - inner_diameter^4) / 32 Note: E*I is also known as flexural rigidity or bending stiffness
OUTPUT: out - only for debugging messages Pts - the list of points that approximate the shape of the elastica Crv - the 3rd-degree curve interpolated from those points (with accurate start & end tangents) L - the length of the rod/wire W - the distance (width) between the endpoints of the rod/wire H - the height of the bent rod/wire A - the tangent angle at the (start) end of the rod/wire F - the force needed to hold the rod/wire in a specific shape (based on the material properties & cross-section) **be sure your units for 'I' match your units for the rest of your inputs (length, width, etc.). Also note that the critical buckling load (force) that makes the rod/wire start to bend can be found at height=0
THANKS TO: Mårten Nettelbladt (thegeometryofbending.blogspot.com) Daniel Piker (Kangaroo plugin) David Rutten (Grasshopper guru) Euler & Bernoulli (the O.G.'s)
--------------------------------------------------
Edit: More on the math behind this here.
Cheers,
Will
…
Added by Will McElwain at 4:08pm on February 26, 2014
me of the dimensions that changed ( become Diagonal after they were Vertical or Horizontal)
I sometime use Record History in rhino for saving time, but when I change some points of curves or trim curves , I have problems with dimensions (see the two pictures below).
Problem 2 :
After trimming , only two dimensions should be changed depending on their place in changed curves . But what happens is that all the dimensions become crazy!!!!!!
I always use Aligned dimension in rhino. Now I know that dimensionsdo not exist in grasshopper. So I ask you if we have expertise in BV , C#, can we create a script for dimensions or is it impossible ??
If we can , I only need Aligned dimension.
I hope that I find or create a script that can define all points: start and end of curve ribs and create dimensions from grasshopper to rhino directly with or without the ability to change automatically .
Thank you
…
mesh by an infinite plane
Namespace: Rhino.GeometryAssembly: RhinoCommon (in RhinoCommon.dll) Version: 5.0.15006.0 (5.0.20693.0)
Syntax
C#
public Mesh[] Split( Plane plane )
Visual Basic
Public Function Split ( _ plane As Plane _ ) As Mesh()
Parameters
plane
Type: Rhino.Geometry..::..Plane[Missing <param name="plane"/> documentation for "M:Rhino.Geometry.Mesh.Split(Rhino.Geometry.Plane)"]
Return Value
[Missing <returns> documentation for "M:Rhino.Geometry.Mesh.Split(Rhino.Geometry.Plane)"]
See Also
Mesh Class
Rhino.Geometry Namespace
Last updated 3 June 2011 - Robert McNeel and Associates
Send comments on this topic to steve@mcneel.com
Report wishes and bugs: https://github.com/mcneel/rhinocommon/issues
Is this the function?
I have a VB component with this:
a = rhino.Geometry.Mesh.CreateBooleanSplit(x, y)
but this is a boolean split, so I have only one mesh, with the intersection. I would like to have several splitted meshes.
Thank you in advance again.
…
rtitions." (http://wias-berlin.de/software/index.jsp?id=TetGen&lang=1)
To continue with my wrapping career, TetRhino (or Tetrino) is a .NET wrapper for the well-known and pretty amazing TetGen mesh tetrahedralization program. It provides one new GH component for discretizing or remeshing objects using TetGen. Basic tetrahedralization functionality is exposed with a few different output types that can be controlled. At the moment, the only control for tetrahedra sizes is the minimum ratio, which is controlled by a slider. This is hardcoded to always be above 1.0-1.1, as it is very easy to generate a LOT of data (and crash)...
The libs are divided again into different modules to allow flexibility and fun with or without Rhino and GH, so have fun. All 4 libs should be placed in a folder (maybe called 'tetgen') in your GH libraries folder. Remember to unblock.
Once again, the libs are provided as-is, with no guarantee of support for now, as I use them internally and do not intend to develop this into a shiny, polished plug-in. If there is enough interest, I can tidy up the code-base and upload it somewhere if someone more savvy than me wants to play.
TetgenGH.gha - Grasshopper assembly which adds the 'Tetrahedralize' component to Mesh -> Triangulation.
TetgenRC.dll - RhinoCommon interface to the Tetgen wrapper.
TetgenSharp.dll - dotNET wrapper for Tetgen.
TetgenWrapper.dll - Actual wrapper for Tetgen.
Obviously, credit where credit is due for this excellent and tiny piece of software:
"The development of TetGen is executed at the Weierstrass Institute for Applied Analysis and Stochastics in the research group of Numerical Mathematics and Scientific Computing." See http://wias-berlin.de/software/index.jsp?id=TetGen&lang=1 for more details about TetGen.
To wrap up, some notes about the inputs:
These are the possible integer Flags (F) values and resultant outputs for the GH component:
0 - Output M yields a closed boundary mesh. Useful for simply remeshing your input mesh.
1 - Output M yields a list of tetra meshes.
2 - Output I yields a DataTree of tetra indices, grouped in lists of 4. Output P yields a list of points to which the tetra indices correspond.
3 - Output I yields a DataTree of edge indices, grouped in lists of 2. Output P yields a list of points to which the edge indices correspond. Useful for lots of things, very easy to create lines from this to plug into K2 or something for some ropey FEA (or not so ropey!) ;)
As this component can potentially create a LOT of data, especially with dense meshes, care should be taken with the MinRatio (R) input. This will try to constrain the tetra to be more or less elongated, which also means that the lower this value gets, the more tetra need to be added to satisfy this constraint. Start with very high values and lower them until satisfactory.
Hopefully shouldn't be an issue, but it's possible that you need the 2015 Microsoft C++ Redistributable.
Happy tetrahedralizing...
UPDATE: The tetgen.zip has been updated with some fixes.
UPDATE2: This is now available on Food4Rhino: http://www.food4rhino.com/app/tetrino
…
Added by Tom Svilans at 1:27am on October 24, 2017
re are major changes and enhancements.
HONEYBEE
More Flexible Workflow - Many small modifications were made to support a more flexible workflow, such as the ability to separate a zone created with masses2Zones into editable HBSrfs that can be recombined. For the energy components, it is now possible to plug custom constructions directly into the components that set the zone constructions without writing them first into the library. For the daylighting components it is now possible to change all of the materials of specific surface types at once.
Support for Complex Geometry - Many small bugs for complex geometry have been fixed including the ability to import energy results correctly for curved NURBS surfaces as well as unconventional window configurations. Also, the intersectMasses component now almost always succeeds in splitting all of the surfaces of adjacent zones, no matter how complex the intersection is.
Automatic Download Issues Fixed - Many users who faced issues with not having “gendaymtx.exe” or who had trouble syncing with our github know that we faced an issue with automatic background downloads.
Air Walls - Honeybee EnergyPlus models now officially support air walls (or virtual partitions) in a basic implementation. Now, any time that you use the air wall construction or set a surface type to “air wall,” the air between adjacent zones will be automatically mixed. At present, this mixing is just a constant flow based on the surface area between zones connected by air walls multiplied by an adjustable “flow factor.” It is important to stress that this basic air mixing is not with the EnergyPlus Airflow Network, although the groundwork laid in this release will eventually allow for the implementation of the Airflow Network in future releases. As such, this present air mixing is only suitable for multi-zone conditions where there is not significant buoyancy-driven flow between zones.
Natural Ventilation - To go along with the new potential introduced by air walls, there has been a basic implementation of EnergyPlus’s natural ventilation objects in a new component called “Set EP Airflow”. The current setup allows for three possible types of natural ventilation: 1) natural ventilation through windows (with auto-calculated flow based on window area, outdoor wind speed/direction, and stack effects), 2) custom wind and stack objects that can be used to model things such as chimneys off of single zones, and 3) constant, fan-driven natural ventilation.
Additional Thermal Mass - The capability to add additional thermal mass to zones has been added. This is useful for factoring in the mass of indoor furniture or heavy interior objects such as chimneys.
New Utility Components - Abraham has added a couple of useful components to help calculate lighting loads based on bulb types and target lighting levels as well as a converter from ACH to the m3/s-m2 that the other HB components accept. Along this vein, there is also a component for adding in the resistance of Air Films to HB constructions.
Improved and Editable Ideal Air Loads System - The EnergyPlus Ideal Air System now goes through an automatic sizing period at the start of the simulation based on the extreme weeks of the weather file. Furthermore, the ability to adjust many of the parameters of the ideal air loads system have been added with a new “Set Ideal Air Loads Parameters” component. The component allows you to add in heat recovery, air side economizers and demand-controlled ventilation.
OpenStudio Export Update - The OpenStudio workflow is still largely under development but this release includes a version with a working VAV and PTHP system template for those curious with experimenting. Note that not all of the new features available for the basic “Run Energy Simulation” component are available for the OpenStudio component (such as air walls, natural ventilation, or additional thermal mass).
Microclimate/Indoor Comfort Maps - Blossoming from initial experiments with the radiant temperature map, a workflow for looking into sub-zone microclimate and indoor comfort has been initiated. All components for this are presently under the Honeybee WIP tab but, over the next month, they will be completing their development phase and moving into the rest of the tabs. If you are interested in testing when they are ready, please let Chris know. For a teaser video of the intended capabilities, see this video: (https://www.youtube.com/watch?v=fNylb42FPIc&list=UUc6HWbF4UtdKdjbZ2tvwiCQ)
LADYBUG
Monthly Bar Chart - After much demand from multiple parties, a new component to create monthly bar and line charts has been added. The component is particularly useful for plotting the outputs of the “Average Data” component like monthly EPW data or averaged monthly-per hour data. It also supports daily data and any type of Energy simulation results.
Wind Profile - To go along with the new capabilities of natural ventilation in Honeybee, Ladybug now has a fully fleshed-out Wind Profile component that allows you to visualize how wind speed changes with height in relation to your building geometry. The component is geared to understanding the conditions of prevailing wind and will be useful in the future for setting up CFD models. Credit goes to Djordje Spasic for adding in all of the new capabilities. In a similar vein, the appearance of the wind rose has also been improved thanks to suggestions from Alejandra Menchaca.
Faster Solar Adjusted Temperature - Thanks to the SolarCal method from the Center for the Built Environment at UC Berkeley (http://escholarship.org/uc/item/89m1h2dg), the solar adjusted temperature component now includes an option for a much faster calculation that produces results that are very close to those originally obtained with the genCumSky component. Instead of using the cumulative sky, the component can now accept the direct and diffuse radiation from the ImportEPW component. Over a whole year, this essentially takes a calculation that used to be a half-hour and shrinks it down to 10 seconds. Thanks again to those at UC Berkeley for keeping their work open source!
Instructions - Last but not the least, [It took me almost two years to understand this but finally] we have a text file that describes the installation step by step and is way easier to modify than a video. You can find it in the zip file. Credit goes to Chris!
We also want to welcome Anton, Patrick and Sandeep to the team. Anton has kicked off his development by working on a component to import and visualize epw ground temperature data and he will be continuing to develop components to bring in reliable precipitation data to Ladybug. With this basis, he will continue to implement Honeybee components for ground heat storage, earth tubes, rain collection and hot water systems. Patrick and Sandeep are working on integration of Honeybee to Energy Performance Calculator.
As always let us know your comments and suggestions.
Enjoy!…
curve or locus] of a segment AB, in English. The set of all the points from which a segment, AB, is seen under a fixed given angle.
When you construct l'arc capable —by using compass— you obviously need to find the centre of this arc. This can be easily done in GH in many ways by using some trigonometry (e.g. see previous —great— solutions). Whole circles instead of arcs provide supplementary isoptics —β-isoptic and (180º-β)-isoptic—. Coherent normals let you work in any plane.
Or you could just construct β-isoptics of AB by using tangent at A (or B). I mean [Arc SED] component.
If you want the true β-isoptic —the set of all the points— you should use {+β, -β} degrees (2 sides; 2 solutions; 2 arcs), but slider in [-180, +180] degrees provides full range of signed solutions. Orthoptic is provided by ±90º. Notice that ±180º isoptic is just AB segment itself, and 0º isoptic should be the segment outside AB —(-∞, A] U [B, +∞)—. [Radians] component is avoidable.
More compact versions can be achieved by using [F3] component. You can choose among different expressions the one you like the most as long as performs counter clockwise rotation of vector AB, by 180-β degrees, around A; or equivalent. [Panel] is totally avoidable.
Solutions in XY plane —projection; z = 0—, no matter A or B, are easy too. Just be sure about the curve you want to find the intersection with —Curve; your wall— being contained in XY plane.
A few self-explanatory examples showing features.
1 & 5 1st ver. (Supplementary isoptics) (ArcCapableTrigNormals_def_Bel.png)
2 & 6 2nd ver. (SED) (ArcCapableSED_def_Bel.png)
3 & 7 3rd ver. (SED + F3) (ArcCapableSEDF3_def_Bel.png)
4 & 8 4th ver. (SED + F3, Projection) (ArcCapableSEDProjInt_def_Bel.png)
If you want to be compact, 7 could be your best choice. If you prefer orientation robustness, 5. Etcetera.
I hope these versions will help you to compact/visualize; let me know any feedback.
Calculate where 2 points [A & B] meet at a specific angle is just find the geometrical locus called arco capaz in Spanish, arc capable in French (l'isoptique d'un segment de droite) or isoptic [curve or locus]
of a segment AB, in English. The set of all the points from which a segment,
AB, is seen under a fixed given angle.…
e a fundamental failure on my part. On the other hand, Grasshopper isn't supposed to be on a par with most other 3D programs. It is emphatically not meant for manual/direct modelling. If you would normally tackle a problem by drawing geometry by hand, Grasshopper is not (and should never be advertised as) a good alternative.
I get that. That’s why that 3D shape I’m trying to apply the voronoi to was done in NX. I do wonder where the GUI metaphor GH uses comes from. It reminds me of LabVIEW.
"What in other programs is a dialog box, is 8 or 10 components strung together in grasshopper. The wisdom for this I often hear among the grasshopper community is that this allows for parametric design."
Grasshopper ships with about 1000 components (rounded to the nearest power of ten). I'm adding more all the time, either because new functionality has been exposed in the Rhino SDK or because a certain component makes a lot of sense to a lot of people. Adding pre-canned components that do the same as '8 or 10 components strung together' for the heck of it will balloon the total number of components everyone has to deal with. If you find yourself using the same 8 to 10 components together all the time, then please mention it on this forum. A lot of the currently existing components have been added because someone asked for it.
It’s not the primary components that catalyzed this thought but rather the secondary components. I was toying with a component today (twist from jackalope) that made use of three toggle components. The things they controlled are checkboxes in other apps.
Take a look at this jpg. Ignore differences; I did 'em quickly. GH required 19 components to do what SW did with 4 commands. Note the difference in screen real estate.
As an aside, I really hate SolidWorks (SW). But going forward, I’ll use it as an example because it’s what most people are familiar with.
"[...] has a far cleaner and more intuitive interface. So does SolidWorks, Inventor, CATIA, NX, and a bunch of others."
Again, GH was not designed to be an alternative to these sort of modellers. I don't like referring to GH as 'parameteric' as that term has been co-opted by relational modellers. I prefer to use 'algorithmic' instead. The idea behind parameteric seems to be that one models by hand, but every click exists within a context, and when the context changes the software figures out where to move the click to. The idea behind algorithmic is that you don't model by hand.
I agree, and disagree. I believe parametric applies equally to GH AND SW, NX, and so forth, while algorithmic is unique to GH (and GC and Dynamo I think). Thus I understand why you prefer the term. I too tend to not like referring to GH as a parametric modeler for the same reason.
But I think it oversimplifies it to say parametric modelers move the clicks. SW tracks clicks the same way GH does; GH holds that information in geometry components while SW holds it in a feature in the feature tree. In both GH and SW edits to the base geometry will drive a recalculation, but more commonly, it’s an edit to input data, beit equations or just plain numbers, that drive a recalculation.
I understand the difference in these programs. What brought me to GH is that it can create a visual dialog that standard modelers can’t. But as I've grown more comfortable with it I’ve come to realize that the GUI of GH and the GUI of other parametric modelers, while looking completely different, are surprisingly interchangeable. Do not misconstrue that I’m suggesting that GH should replace it’s GUI with SW’s. I’m not. I refrain from suggesting anything specific. I only suggest that you allow yourself to think radically.
This is not to say there is no value in the parametric approach. Obviously it is a winning strategy and many people love to use it. We have considered adding some features to GH that would make manual modelling less of a chore and we would still very much like to do so. However this is such a large chunk of work that we have to be very careful about investing the time. Before I start down this road I want to make sure that the choice I'm making is not 'lame-ass algorithmic modeller with some lame-ass parametrics tacked on' vs. 'kick-ass algorithmic modeller with no parametrics tacked on'.
Given a choice, I'd pick kick-ass algorithmic modeller with no parametrics tacked on.
2. Visual Programming.
I'm not exactly sure I understand your grievance here, but I suspect I agree. The visual part is front and centre at the moment and it should remain there. However we need to improve upon it and at the same time give programmers more tools to achieve what they want.
I'll admit, this is a bit tough to explain. As I've re-read my own comment, I think it was partly a precursor to the context sensitivity point and touched upon other stated points.
This now touches upon my own ignorance about GH’s target market. Are you moving toward a highly specialized tool for programmers and/or mathematicians, or is the intent to create a tool that most designers can master? If it’s the former, rock on. You’re doing great. If it’s the latter, I’m one of the more technically sophisticated designers I know and I’m lost most of the time when using GH.
GH allows the same freedom as a command line editor. You can do whatever you like, and it’ll work or not. And you won’t know why it works or doesn't until you start becoming a bit of an expert and can actually decipher the gibberish in a panel component. I often feel GH has the ease of use of DOS with a badass video card in front.
Please indulge my bit of storytelling. Early 3D modelers, CATIA, Unigraphics, and Pro-Engineer, were unbelievably difficult to use. Yet no one ever complained. The pain of entry was immense. But once you made it past the pain threshold, the salary you could command was very well worth it. And the fewer the people who knew how to use it, the more money you could demand. So in a sense, their lack of usability was a desirable feature among those who’d figured it out.
Then SolidWorks came along. It could only do a fraction of what the others did, but it was a fraction of the cost, it did most of what you needed, and anyone could figure it out. There was even a manual on how to use it. (Craziness!) Within a few short years, the big three all had to change their names (V5, NX, and Wildfire (now Creo)) and change the way they do things. All are now significantly easier to use.
I can tell that the amount of development time that’s gone into GH is immense and I believe the functionality is genius. I also believe it’s ease of use could be greatly improved.
Having re-read my original comments, I think it sounded a bit snotty. For that I apologize.
3. Context sensitivity.
"There is no reason a program in 2014 should allow me to make decisions that will not work. For example, if a component input is in all cases incompatible with another component's output, I shouldn't be able to connect them."
Unfortunately it's not as simple as that. Whether or not a conversion between two data types makes sense is often dependent on the actual values. If you plug a list of curves into a Line component, none of them may be convertible. Should I therefore not allow this connection to be made? What if there is a single curve that could be converted to a line? What if you want to make the connection now, but only later plan to add some convertible curves to the data? What you made the connection back when it was valid, but now it's no longer valid, wouldn't it be weird if there was a connection you couldn't make again?
I've started work on GH2 and one of the first things I'm writing now is the new data-conversion logic. The goal [...] is to not just try and convert type A into type B, but include information about what sort of conversion was needed (straightforward, exotic, far-fetched. etc.) and information regarding why that type was assigned.
You are right that under some conditions, we can be sure that a conversion will always fail. For example connecting a Boolean output with a Curve input. But even there my preferred solution is to tell people why that doesn't make sense rather than not allowing it in the first place.
You bring up both interesting points and limits to my understanding of coding. I’ve reached the point in my learning of GH where I’m just getting into figuring out the sets tab (and so far I’m not doing too well). I often find myself wondering “Is all of this manual conditioning of the data really necessary? Doesn’t most software perform this kind of stuff invisibly?” I’d love to be right and see it go away, but I could easily be wrong. I’ve been wrong before.
5. Components.
"Give components a little “+” or a drawer on the bottom or something that by clicking, opens the component into something akin to a dialog box. This should give access to all of the variables in the component. I shouldn't have to r-click on each thing on a component to do all of the settings."
I was thinking of just zooming in on a component would eventually provide easier ways to access settings and data.
I kinda like this. It’s a continuation of what you’re currently doing with things like the panel component.
"Could some of these items disappear if they are contextually inappropriate or gray out if they're unlikely?"
It's almost impossible for me to know whether these things are 'unlikely' in any given situation. There are probably some cases where a suggestion along the lines of "Hey, this component is about to run 40,524 times. It seems like it would make sense to Graft the 'P' input." would be useful.
6. Integration.
"Why isn't it just live geometry?"
This is an unfortunate side-effect of the way the Rhino SDK was designed. Pumping all my geometry through the Rhino document would severely impact performance and memory usage. It also complicates the matter to an almost impossible degree as any command and plugin running in Rhino now has access to 'my' geometry.
"Maybe add more Rhino functionality to GH. GH has no 3D offset."
That's the plan moving forward. A lot of algorithms in Rhino (Make2D, FilletEdge, Shelling, BlendSrf, the list goes on) are not available as part of the public SDK. The Rhino development team is going to try and rectify this for Rhino6 and beyond. As soon as these functions become available I'll start adding them to GH (provided they make sense of course).
On the whole I agree that integration needs a lot of work, and it's work that has to happen on both sides of the isle.
You work for McNeel yet you seem to speak of them as a separate entity. Is this to say that there are technical reasons GH can only access things through the Rhino SDK? I’d think you would have complete access to all Rhino API’s. I hope it’s not a fiefdom issue, but it happens.
7. Documentation.
Absolutely. Development for GH1 has slowed because I'm now working on GH2. We decided that GH1 is 'feature complete', basically to avoid feature creep. GH2 is a ground-up rewrite so it will take a long time until something is ready for testing. During this time, minor additions and of course bug fixes will be available for GH1, but on a much lower frequency.
Documentation is woefully inadequate at present. The primer is being updated (and the new version looks great), but for GH2 we're planning a completely new help system. People have been hired to provide the content. With a bit of luck and a lot of work this will be one of the main selling points of GH2.
It begs the question that I have to ask. When is GH1.0 scheduled to launch? And if you need another person to proofread the current draft of new primer.
patrick@girgen.com
I can’t believe wikipedia has an entry for feature creep. And I can’t believe you included it. It made me giggle. Thanks.
8. 2D-ness.
"I know you'll disagree completely, but I'm sticking to this. How else could an omission like offsetsurf happen?"
I don't fully disagree. A lot of geometry is either flat or happens inside surfaces. The reason there's no shelling (I'm assuming that's what you meant, there are two Offset Surface components in GH) is because (a) it's a very new feature in Rhino and doesn't work too well yet and (b) as a result of that isn't available to plugins.
I believe it’s been helpful for me to have figured this out. I recently completed a GH course at a local Community College and have done a bunch of online tutorials. The first real project I decided to tackle has turned out to be one of the more difficult things to try. It’s the source of the questions I posted. (Thanks for pointing out that they were posted in the wrong spot. I re-posted to the discussions board.)
I just can't seem to figure out how to turn the voronoi into legitimate geometry. I've seen this exact question posted a few times, but it’s never been successfully answered. What I'm showing here is far more angular than I’m hoping for. The mesh is too fine for weaverbird to have much of an effect. And I haven't cracked re-meshing. Btw, in product design, meshes are to be avoided like the plague. Embracing them remains difficult.
As for offsetsurf, in Rhino, if you do an offsetsurf to a solid body, it executes it on all sides creating another neatly trimmed body thats either larger or smaller than the original. This is how every other app I know of works. GH’s offsetsurf creates a bunch of unjoined faces spaced away from the original brep. A common technique for 3D voronois (Yes, I hit the voronoi overuse easter egg) is to find the center of each cell and scale them by this center. If you think about it, this creates a different distance from the face of the scaled cell to the face of the original cell for every face. As I've mentioned, this project is giving me serious headaches.
Don't get me wrong, I appreciate the feedback, I really do, but I want to be honest and open about my own plans and where they might conflict with your wishes. Grasshopper is being used far beyond the boundaries of what we expected and it's clear that there are major shortcomings that must be addressed before too long. We didn't get it right with the first version, I don't expect we'll get it completely right with the second version but if we can improve upon the -say- five biggest drawbacks (performance, documentation, organisation, plugin management and no mac version) I'll be a happy puppy.
--
David Rutten
Thank you for taking the time to reply David. Often we feel that posting such things is send it into the empty ether. I’m very glad that this was not the case.
And thank you for all of the work you've put into GH. If you found any of my input overly harsh or ill-mannered, I apologise. It was not my intent. I'm generally not the ranting sort. If I hadn't intended to provide possibly useful input, I wouldn't have written.
Cheers
Patrick Girgen
Ps. Any pointers on how to get a bit further on the above project would be greatly appreciated.
…
Karamba.
I am using your plug-in for normal forces evaluation in the transvere wires and spreaders of a sailboat. Mast is solved in another way, so I am not taking forces from Karamba in that case.
Basing on the forces value an adequate wire size (diameter) is choosen. Then masses of wires are being calculated. Loads (forces) on longitudinal wires are calculated without Karamba. The problem is when choosing transverse wires’ mass minimization as a criteria, the Octopus doesn’t get any results - is changing the sliders (genes) too fast for Karamba to calculate the forces (so Octopus gets only nulls):
When minimization of a e.g. longitudinal wires’ mass (calculated without Karamba) is taken as a criteria Octopus works fine.
Which suggests that the problem is in interaction of two plug-ins.
Any ideas how to avoid that problem?
Thanks,
M.
Below some screenshots of definition part with Karamba:
1675×807 200 K
image.png1680×789 398 KB
Despite the ‘orange warning’ the values are correct (double checked with other software).However I don't know why does it say that there is a part that can move freely without deformation,as the model looks like this:
image.png1239×343 55.5 KB
…