ut in the next few days.
I've found getting really good handling of static vs kinetic friction to be a pain though.
Distinguishing between collisions and resting contact generally becomes more complicated than it might first appear.
If the collision with the mesh or ground is 'hard' I project the particle positions, so they can never penetrate, and reverse the component of their velocity normal to the surface (multiplied by the restitution factor). This means that whenever you have some structure of springs resting on a hard surface, there is usually still some tiny imperceptible bouncing. This makes it hard to properly apply static friction (which would zero the tangential velocity if the tangential force was below some threshold and it is not already sliding), because particles are generally not perfectly on the surface, even when apparently at rest. Obviously it's not good to have friction affecting things that aren't touching the surface.
This is the origin of the 'settle' parameter in the settings. The idea was that when the motion of a particle normal to the surface drops below that limit, it will be totally zeroed, and the particle becomes properly resting on the surface. I never really like having to use these kind of weird ad hoc fixes though.
Alternatively, if the collision is 'soft' I use a spring-like force to push particles out of the ground/mesh.
This can cause problems because in many cases you just want a simple constraint that they never go below ground level, and there is a limit to how stiff you can make these spring-like forces.
The advantage though, is that because any particle resting 'on' the ground/surface will actually be slightly below/inside it, and one can use this to decide whether to apply contact friction.
With bouncing collisions, it is a little simpler. There is just the question of what to do with the velocity component tangential to the surface. See the bottom comment by me here, for more on the 'tumble' setting:
http://www.grasshopper3d.com/video/kangaroo-traction-test
So you see, it is challenging to get one consistent model that will give correct behaviour for all cases (eg a simple static 'leaning ladder' type problem, a bouncing particle, and vehicle wheel traction), without having several of these odd seeming and non-intuitive settings.
…
Added by Daniel Piker at 11:11am on October 18, 2012
m is different from email spam.
Email spammers want you to buy their product. You are the target of the ad contained in each email spam you receive. Comment/web spammers want your readers to buy their product. You (the blogger, author, moderator) are not the target.
2. Web spammers are social engineers.
Email spammers write messages to get your attention. Comment spammers write messages to escape your attention. They want you to believe they are real bloggers, real people, writing real comments, so you’ll approve the comment and publish it on your site. They use flattery, appeal to your good nature, and simply lie in order to convince you to give them the benefit of the doubt.
3. Web spammers are basically advertising on your blog..
..and they're keeping all of the profits. They’re not even asking your permission first. Right now someone is offering to sell links from your blog to anyone willing to pay a few dollars (or a few cents). If your blog is well known, it may even be listed by name, with backlinks for sale at a set price.
4. It’s all about the backlinks.
Web spammers are selling links from your blog to their clients. They do this to game the search engines and trick your readers into visiting dubious web sites. Their clients are sometimes seemingly harmless, but are often peddling fake pills, porn, scams and malware. Sometimes they’ll use “buffer sites” – that is, innocent looking web pages intended to disguise the fact that they’re really advertising something more sinister.
5. Spammers employ humans.
Not all spam is delivered by spambots. Spammers are increasingly using humans to write and post comments by hand. Typically they are exploiting low-paid workers in internet cafes, schools and factories. Sometimes they are viral marketers paid to promote a new product. Either way they are trying to exploit your blog for their profit – and hoping to do it without you noticing.
…
Added by Danny Boyes at 4:51am on October 24, 2013
he results are accurate enough.Good to go!Current working directory is set to: C:\002_VIDEO\02_UNI\TU_GRAZ\01_DISSERTATION\02_RESEARCH\08_POMODORO\01_SIMULATION_MODEL/03_HONEYBEE\VF_00\gridBasedSimulation\start cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineRuntime error (IndexOutOfRangeException): index out of range: 0Traceback: line 271, in script…
is set to: C:\002_VIDEO\02_UNI\TU_GRAZ\01_DISSERTATION\02_RESEARCH\08_POMODORO\01_SIMULATION_MODEL/03_HONEYBEE\VF_00\gridBasedSimulation\start cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get Commandlinestart cmd /c C:\Users\paratufello\AppData\Roaming\Ladybug\unnamed\annualSimulation\unnamed_7_DS.batWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineWMIC PROCESS get CommandlineRuntime error (IndexOutOfRangeException): index out of range: 0Traceback: line 271, in script…
dy for a wall where we want to analyze its openings. I made a parametric wall that then get's analyzed with different geometries and the idea was just to leave it there for the weekend as it morphed through different iterations. However, after successfully running a test simulation on my pc (just with one iteration), it fails to run the same test on the workplace computer. Any help would be greatly apprecated! Here is the following error:
Sorry! But the number of available CPUs on your machine is 4.
Honeybee set the number of CPUs to 4.
Grid-based Radiance simulation
The component is checking ad, as, ar and aa values. This is just to make sure that the results are accurate enough.
Good to go!
Current working directory is set to: C:\ladybug\Parametric_Shading_Wall\psw_z0.25_t.025_y.2_r90_m3_lux\gridBasedSimulation\
Failed to read the results!
rtrace: fatal - (psw_z0.25_t.025_y.2_r90_m3_lux_RAD.oct): truncated octree
rtrace: fatal - (psw_z0.25_t.025_y.2_r90_m3_lux_RAD.oct): truncated octree
rtrace: fatal - (psw_z0.25_t.025_y.2_r90_m3_lux_RAD.oct): truncated octree
rtrace: fatal - (psw_z0.25_t.025_y.2_r90_m3_lux_RAD.oct): truncated octree
Runtime error (PythonException): Failed to read the results!
rtrace: fatal - (psw_z0.25_t.025_y.2_r90_m3_lux_RAD.oct): truncated octree
rtrace: fatal - (psw_z0.25_t.025_y.2_r90_m3_lux_RAD.oct): truncated octree
rtrace: fatal - (psw_z0.25_t.025_y.2_r90_m3_lux_RAD.oct): truncated octree
rtrace: fatal - (psw_z0.25_t.025_y.2_r90_m3_lux_RAD.oct): truncated octree
PS. It says to see line 336…
answer further on Friday.
The "ghdoc" variable and rhinoscriptsyntaxThe ghdoc variable is provided by the component if you select it as "target".You might ask yourself: "why do we need it"?Its use comes from the very design of the established RhinoScript library. This library is imperative, which means it is build from a set of procedures or functions that act on various geometrical types. Additionally, there is one level of indirection: most of the time, the user does not work with the geometry itself in the variable, but rather with Guid of geometry that is present in a document. This is exactly what ghdoc is: it is the document that the RhinoScript library always implicitly targets with all AddSomething() calls (for example, AddLine()).
Based on this comment...RhinoScript use within GhPython may be less idealThat comment is from a previous version of this component that did not have the ghdoc yet.With the ghdoc variable, the standard Rhino document target of RhinoScript is replaced, therefore we can use Grasshopper while leaving the Rhino document unchanged. This saves uncountable Undo's, and makes it easy to structure ideas through the definition graph
...is the rhinoscriptsyntax target irrelevant if using solely RhinoCommon classesYes. If you create class instances (objects), you will need to create also your own collection objects to store them (mostly lists, trees). You can imagine the ghdoc as being an alternative to them, just that you do not access data by index (number), but by Guid. So you can use the RhinoScript or the RhinoCommon libraries independently or mix them. The RhinoScript implementation in Rhino is open-source and is all written in RhinoCommon. Also the ghdoc implementation is open-source, and is here.
RhinoScript and/or RhinoCommon objects which are not recognized as valid Grasshopper geometryYes, sure, Grasshopper handles only a portion of all available types. Basically, unhandled types are all the types that do not exists in the 'Params' tab. For example, there is no textdot and no leader, so on line 149 there is a throw statement and all TextDot calls (about line 350) are commented out. When/if Grasshopper one day will support these types, these calls will be implemented.
DataTreeHere is a small sample. However, I think that 80% of the times it is not necessary to program for DataTrees, as the logic itself can be applied per-list and Grasshopper handles list-iteration.
I hope this helps,
- Giulio_______________giulio@mcneel.comMcNeel Europe…
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…
ch of your tree is identified by an "address". In order to match the data in two separate trees for successfully computation, it is best for the addresses of each tree branch to be in the same format; i.e., with the same number of place holders. For instance, {0;0;1} vs {0:1} vs {1}. I think of the path mapper component more like a "tree branch address format changer". It does not manipulate the branches, it merely manipulates the branch "addresses". You use the other logic components from the list menu, sets menu, or tree menu to select particular branches or subsets of branches.
The post by Sameer Kumar on December 7, 2009 was the post that finally helped me over the hump you are trying to get over. It is most understandable and well illustrated regarding the path mapper purpose.
http://www.grasshopper3d.com/forum/topics/path-mapper-component-what?xg_source=activity
One side note, I have noticed that grasshopper will match data that is not perfectly in the same branch address format. But I have not yet figured out the logic of how this works exactly. Perhaps someone with a better grasp could explain how GH matches data when the paths are not perfectly mapped. Understanding this less formal logic might eliminate the need to employ the path mapper every time.
Good Luck
Stan…
Added by Stan Carroll at 6:31am on August 11, 2010
mplex geometries.
How high level am I talking about? Mostly exploring large scale fabricate-able complex geometries. My current practice is centered on designing/fabricating Public Art via abstract sculpture. I fabricate all my work, mostly in metal. I am currently engaging computational methods in nearly all of my sculptural work. I live in Oklahoma City, USA where there is a huge lack of knowledge regarding high level digital methods, consequently, I have hit a plateau on my learning since virtually all the knowledge I possess has been self acquired via my own initiative and a great beginner seminar early on at Acadia 2009 with Akos and Parsons.
I have two primary goals: Priority 1) to extend my knowledge/methods regarding fabricate-able complex geometry to the next level and secondarily, I have an interest in someday teaching full time at the university level which typically requires at least a masters degree. I am currently an adjunct Professor at University of Oklahoma and Oklahoma State University.
I hope this additional information might focus your and other responses to my question. My direct email is scarroll@beyondmetal.com if anyone would like to contact me offline.
Thanks again,
Stan Carroll…
Added by Stan Carroll at 7:58am on February 4, 2013
sting for two reasons. One, it gave an example of U calculation of a typical green wall system (values could be similar for a green roof) which allows for the simulation of greenery over a wall or roof material. The system was something like the below (with the interesting r-values attached):
LAYER R-value
Outside air film
Turfing 0.360
Substrate (0.1m) 1.923
Air gap (0.1m)
Wall
Inside air film
The second reasons was an equation they were using to calculate the shading coefficient of the greenery. In the literature, the leaf density is usually correlated with the shading coefficient of the greenery, which makes sense. This isn't as interesting for green roofs but it does provide a simple way to simulate green walls over fenestration. The correlation equation between LAI and SC was this one:
Shading coefficient (y) = -0.3043 x Leaf area index (x) + 0.8112
I used this equation in a couple of examples to calculate the SC of vertical green walls.
Hope this is interesting.
Regards,
Theodore.…