n make it possible to Motivation generate
a variety of interesting objects, from abstract fractals to plant-like
branching structures, their modeling power is quite limited. A major
problem can be traced to the reduction of all lines to integer multiples
of the unit segment. As a result, even such a simple figure as an
isosceles right-angled triangle cannot be traced exactly, since the ratio
of its hypotenuse length to the length of a side is expressed by the irrational
number √2. Rational approximation of line length provides only
a limited solution, because the unit step must be the smallest common
1
1
√2
denominator of all line lengths in the modeled structure. Consequently,
the representation of a simple plant module, such as an internode, may
require a large number of symbols. The same argument applies to angles.
Problems become even more pronounced while simulating changes
to the modeled structure over time, since some growth functions cannot
be expressed conveniently using L-systems. Generally, it is difficult
1.10. Parametric L-systems 41
to capture continuous phenomena, since the obvious technique of discretizing
continuous values may require a large number of quantization
levels, yielding L-systems with hundreds of symbols and productions.
Consequently, model specification becomes difficult, and the mathematical
beauty of L-systems is lost.
In order to solve similar problems, Lindenmayer proposed that numerical
parameters be associated with L-system symbols [83]. He illustrated
this idea by referring to the continuous development of branching
structures and diffusion of chemical compounds in a nonbranching filament
of Anabaena catenula.
The following is an example of its application:
starting string: A
p1: A F(1)[+A][-A]
P2: F(s) F(s*R)
which I think is basically trying to say
F(s) = move forwar a step of length s > 0.
Thanks again,
Mateo…
" (idiomatic) and easy way of doing things.So here come some basic questions:
Is there a way to create custom components by grouping an existing sub-network together? I'm looking for a way to re-use parts of a program (something similar to subroutines), and to make the network look less cluttered. I found that it is possible to group components (ctrl-g), but this still displays them as separate blocks (too much clutter), and provides no way to re-use a sub-network in such a way that if it is modified in one place, all it's instances (all the places where it is re-used) also get modified.
Is there a component that does nothing, just passes a signal through? Suppose I need to connect block A to blocks B1, B2, B3 (all three get the same input). Then I change my mind, and I decide to connect block C to these three, not A. In this case it will be necessary to change three connections, not just one. I'm looking for an easy way to do this by a single rewiring, not three. (This came up in a practical situation).
Finally, a related question: is there a component that acts as a switch, so I can choose which signal it passes through out of a possible set of choices? For example, suppose that a set of objects can be coloured based on a number of different properties (size, positions, rotation, etc.) I'm looking for a way to switch between these very easily, without the need to do much rewiring.
Thank you in advance for any replies / useful comments, even general ones on how to easily structure a large Grasshopper program/network.…
ake a modest notice about the two new Ladybug components, one of which creates a 3d terrain shading mask and another one which visualizes and exports horizon angles. A terrain shading mask is essentially a diagram which maps the silhouette of the surrounding terrain (hills, valleys, mountains, tree tops...) around the chosen location, and account for the shading losses from the terrain. It can be used as a context_ input in mountainous or higher latitude regions for any kind of sun related analysis: sunlight hours analysis, solar radiation analysis, view analysis, photovoltaics/solar water heating sunpath shading...
My home town is an example of the shading caused by the terrain. Here is how it looks from the tallest building in the town:
And the created terrain shading mask:
A mask for any land location up to 60 degrees North can be created:
There will also be a support for a few major cities above this limit.
Both Terrain shading mask and Horizon angles components can be downloaded from here. An example .gh file can be found in here.
Component will prompt the user to download and copy certain files in order to be able to run.
It was created with assistance from Dr. Bojan Savric. Support on various issues was further given by: Dr. Graham Dawson, Dr. Alec Bennett, Dr. Ulrich Deuschle, Andrew T. Young, LiMinlu, Jonathan de Ferranti, Michal Migurski, Christopher Crosby, Even Rouault, Tamas Szekeres, Izabela Spasic, Mostapha Sadeghipour Roudsari, Dragan Milenkovic, Chen Weiqing, Menno Deij-van Rijswijk and gis.stackexchange.com community.
I hope somebody might find the components useful.…
st between those two applications. But as soon as every frame is re-calculated I noticed that intersection function is very slow. It is actually so slow, that maximum number of polygons to play with is only 10 or less.
Could you help me to find a faster solution for my script?
calculation of intersection lines;
//////////////////////////////////////////////////////////////////////////////////////////
import ghpythonlib.components as ghcompimport rhinoscriptsyntax as rsdef ctr(crv): pts = ghcomp.Explode(crv)[1] pts = ghcomp.CullDuplicates(pts,0.001)[0] return ghcomp.Average(pts)pts = []lines = []ctr_c1 = ctr(C1)for crv in C2: if ctr(crv) != ctr_c1: int = ghcomp.CurveXCurve(C1, crv)[0] if int: [pts.append(x) for x in int] lines.append(rs.AddLine(int[0],int[1]))
/////////////////////////////////////////////////////////////////////////////////////////////
The overall description of the script:
a)Processing+ghowl is used for moving objects and physics
b)python script (slowest part) calculates intersection lines
c)intersected parts of polygons are rotated in 90 degrees.
I have attached grasshopper and processing files. (processing is not necessary to test the script)
Thank you in advance,
Pereas.
…
simple, there are many symetries in 3 main planes. So I used arcs rotated 45° from the main planes and I generate a pentagon which was mirrored and rotated many times.
At the end there are 24 pentagons and 8 hexagons so 32 faces, 54 points/vertex and 84 edges.
It could generate some others tessalation styles
…
on this, but to my understanding, the Δt_pr used is the same - the equations used to calculate are not. Take a look at this (from EN 7730 as well):
If I can make some wishes too; it would be cool, if you included the last local comfort metrics from EN7730 in LB/HB as well. Besides the local asymmetry there are: an equation for warm/cold floors, stratification and draught. I know, that you will need preform a CFD simulation to properly calculate stratification and draught, but the comfort equations are really simple and seeing that you have(might have) a CFD tool under way it could be useful. Anyways I think it would possible to import external generated CFD data to grasshopper.
The pictures in my previous post are from a paper called: "A simplified calculation method for checking the indoor thermal climate" by B.W. Olesen, it can be found in ASHRAE 1983, vol. 25, issue 5. I don't know if there have been any updates to it since '83.
Looking forward for the new components, and if there is anything I can help with please let me know.
/Christian
…
ce attractors
3- Relation between mathematics and Form
4- Network surface and Paneling
5- Fabrication methods (slice3d, nesting, ...)
6- Structure and Architecture (Millipede)
7-Energy and form
8- Islamic patterns
9- Physics with kangaroo
…
see in my bottom post image there is only one isocurve showing in U and V.
In Grasshopper there's no surface rebuild? Well, the same old Grasshopper Patch command will let you specify spans I guess, to make a surface from a planar curve, but it won't work for things with holes since they will just fill in!
You can recreate a surface painfully by untrimming, adding many UV points, rebuilding from those points, then retrimming with the original surface info, but the retrimming simply fails.
If you make a planar surface from a curve in Rhino, you end up with utterly no point editability:
No wonder my CreatePatch tests were a failure. The starting surface could not be distorted except in the extreme case of moving four corner points!
I have no idea how to successfully rebuild a surface akin to the Rhino rebuild command. It's great to be able to prototype in Grasshopper, but with Python I can rebuild easily ( http://4.rhino3d.com/5/rhinocommon/?topic=html/M_Rhino_Geometry_Surface_Rebuild.htm ;), so I guess I should start a collection, like peter, of little script components for prototyping with.…
Added by Nik Willmore at 6:18am on February 26, 2016
of Space, 1984) and specified in (Turner A. , “Depthmap: A Program to Perform Visibility Graph Analysis, 2007), intuitively describe the difficulty of getting to other spaces from a certain space. In other words, the higher the entropy value, the more difficult it is to reach other spaces from that space and vice-versa. We compute the spatial entropy of the node as using the point depth set:
(11)
“The term is the maximum depth from vertex and is the frequency of point depth *d* from the vertex” (ibid). Technically, we compute it using the function below, which itself uses some outputs and by-products from previous calculations:
Algorithm 4: Entropy Computation
Given the graph (adjacency lists), Depths as List of List of integer, DepthMap as Dictionary of integer
Initialize Entropies as List(double)
For node as integer in range [0, |V|)
integer How_Many_of_D=0
double S_node=0
For depth as integer in range [1, Depths[node].Max()]
How_Many_of_D=DepthMap.Branch[(node,depth)].Count
double frequency= How_Many_of_D/|V|
S_node = S_node - frequency * Math.Log(frequency, 2)
Next
Entropies [node] = S_node
Next
…
edit 29/04/14 - Here is a new collection of more than 80 example files, organized by category:
KangarooExamples.zip
This zip is the most up to date collection of examples at the moment, and collects t