mplex the models are. If we are running multi-room E+ studies, that will take far longer to calculate.
Rhino/Grasshopper = <1%
Generating Radiance .ill files = 88%
Processing .ill files into DA, etc. = ~2%
E+ = 10%
Parallelizing Grasshopper:
My first instinct is to avoid this problem by running GH on one computer only. Creating the batch files is very fast. The trick will be sending the radiance and E+ batch files to multiple computers. Perhaps a “round-robin” approach could send each iteration to another node on the network until all iterations are assigned. I have no idea how to do that but hope that it is something that can be executed within grasshopper, perhaps a custom code module. I think GH can set a directory for Radiance and E+ to save all final files to. We can set this to a local server location so all runs output to the same location. It will likely run slower than it would on the C:drive, but those losses are acceptable if we can get parallelization to work.
I’m concerned about post-processing of the Radiance/E+ runs. For starters, Honeybee calculates DA after it runs the .ill files. This doesn’t take very long, but it is a separate process that is not included in the original Radiance batch file. Any other data manipulation we intend to automatically run in GH will be left out of the batch file as well. Consolidating the results into a format that Design Explorer or Pollination can read also takes a bit of post-processing. So, it seems to me that we may want to split up the GH automation as follows:
Initiate
Parametrically generate geometry
Assign input values, material, etc.
Generate radiance/ E+ batch files for all iterations
Calculate
Calc separate runs of Radiance/E+ in parallel via network clusters. Each run will be a unique iteration.
Save all temp files to single server location on server
Post Processing
Run a GH script from a single computer. Translate .ill files or .idf files into custom metrics or graphics (DA, ASE, %shade down, net solar gain, etc.)
Collect final data in single location (excel document) to be read by Design Explorer or Pollination.
The above workflow avoids having to parallelize GH. The consequence is that we can’t parallelize any post-processing routines. This may be easier to implement in the short term, but long term we should try to parallelize everything.
Parallelizing EnergyPlus/Radiance:
I agree that the best way to enable large numbers of iterations is to set up multiple unique runs of radiance and E+ on separate computers. I don’t see the incentive to split individual runs between multiple processors because the modular nature of the iterative parametric models does this for us. Multiple unique runs will simplify the post-processing as well.
It seems that the advantages of optimizing matrix based calculations (3-5 phase methods) are most beneficial when iterations are run in series. Is it possible for multiple iterations running on different CPUs to reference the same matrices stored in a common location? Will that enable parallel computation to also benefit from reusing pre-calculated information?
Clustering computers and GPU based calculations:
Clustering unused computers seems like a natural next step for us. Our IT guru told me that we need come kind of software to make this happen, but that he didn’t know what that would be. Do you know what Penn State uses? You mentioned it is a text-only Linux based system. Can you please elaborate so I can explain to our IT department?
Accelerad is a very exciting development, especially for rpict and annual glare analysis. I’m concerned that the high quality GPU’s required might limit our ability to implement it on a large scale within our office. Does it still work well on standard GPU’s? The computer cluster method can tap into resources we already have, which is a big advantage. Our current workflow uses image-based calcs sparingly, because grid-based simulations gather the critical information much faster. The major exception is glare. Accelerad would enable luminance-based glare metrics, especially annual glare metrics, to be more feasible within fast-paced projects. All of that is a good thing.
So, both clusters and GPU-based calcs are great steps forward. Combining both methods would be amazing, especially if it is further optimized by the computational methods you are working on.
Moving forward, I think I need to explore if/how GH can send iterations across a cluster network of some kind and see what it will take to implement Accelerad. I assume some custom scripting will be necessary.…
even (0, 2, 4) then that means the point either never hit it, or went in and out again, meaning it's outside. If it hits an odd number of times, then it must have come from within originally.
The method implements this approach using the mesh bounding box, and then striking a polyline from your test point along a vector that is defined by the upper right corner of the bounding box + a vector of (100,100,100). In the case of your failing points, this is a result of their striking an edge very precisely, which gets counted as 2 hits instead of 1 (as it should be getting captured) and passing false:
Your best bet is probably to roll your own implementation, that tests for multiple vectors:
private void RunScript(List<Point3d> P, Mesh M, ref object A, ref object B, ref object C) {
BoundingBox bb = M.GetBoundingBox(false);
List<bool> inside = new List<bool>();
for (int i = 0; i < P.Count; i++) {
Polyline a = new Polyline(); Polyline b = new Polyline();
a.Add(P[i]); b.Add(P[i]);
a.Add(bb.Max + new Vector3d(100, 100, 100)); b.Add(bb.Max + new Vector3d(100, 150, 150));
int[] fa; int[] fb;
Point3d[] xa = Rhino.Geometry.Intersect.Intersection.MeshPolyline(M, new PolylineCurve(a), out fa); Point3d[] xb = Rhino.Geometry.Intersect.Intersection.MeshPolyline(M, new PolylineCurve(b), out fb);
inside.Add(xa.Length % 2 == 1 || xb.Length % 2 == 1);
checkA.AddRange(xa, new GH_Path(i)); checkB.AddRange(xb, new GH_Path(i));
}
A = inside;
}
…
Added by David Stasiuk at 10:20am on October 10, 2017
i have to rely completely in passive means.
To speed things i'm calculating comfort for Extreme hot/cold week, thinking maybe on typical weeks instead.
The cool week is kind of "right", but the hot (extreme) is giving all night hours 100% comfort. Knowing the climate, there is no way this can be the case. Some of the settings with the european standards give sometimes the right tendency, but still, compared to ASHRAE's the average of % percentage is too high.
Also my assumptions for flexibility of use/clothing/etc is the maximal. I mean, no constrains on this respect ("let's be passive as much as we can").
So right now i have no specific questions, but rather your advice, if any: "What you would do ...?? (I don't like these kind of questions, sorry).
A request, yes, if it is possible to output the set temperature for each hour. For instance, when you give the degFromTargetMtx i'll like to know this target. This is for control, and i think this is important for better understanding this black box.
Any other insights you may have, just shoot.
Not related to the discussion, but if you happened to check the model, we are simulating 2 apartments in the building. The northern one is only one thermal zone. The southern is divided in rooms. I wanted to see how much difference e get between both ways. And there is. No doubt the more detailed modeling looks more reliable. Also if you have some points here, shoot again.
BTW humidity, look at page 32-33 in the AC book. Nicol is clear on the "real" influence of the humidity, arguing it is mostly psychological than real.
Thanks again, and to you too Mauricio.
-A.…
till quite rough.
I went through your attached log but it seems to be a successful run, perhaps the error log wasn't attached. In any case, I believe we have identified this issue. The goal of the update fvSchemes component was to apply schemes to finalized meshes in an automatic way. While this is useful for new users it is also a dangerous thing to do in CFD studies.
The component works by relating mesh quality to the mesh non-orthogonality, which the checkMesh component reports. While non-orthogonality is one of the important criteria of mesh quality it does present difficulties on some kind of meshes, especially like the simple cases that BF has been meshing so far.
The example case of simple box buildings in a wind tunnel above for instance will appear as a good quality case for even the lowest of cell-count meshes, simply because it is an orthogonal geometry. That means that checkMesh will probably report low values (imagine an empty blockMesh of 10m blocks has a non-orthogonality of 0) which in turn means that higher order schemes might be paired with actually low quality meshes. This I believe is causing problems.
I posted a possible solution to this here https://github.com/mostaphaRoudsari/Butterfly/issues/57. The idea is that Buttefly provides additional options to the users, enabling them to choose between first-order (faster, more robust, but lower quality schemes) and second-order (slower, less robust, but more accurate) schemes depending on mesh quality, stage of assessment, etc. In cases like the above mesh quality a first-order scheme might provide a better option. To test this I am attaching an fvSchemes file you can use by replacing yours in the /system folder of the case.
As a note however, I would like to stress there is so much that a tool like Butterfly can provide in this area. Meshing is a quite complicated and demanding part of the process, involving a lot of trial and error. Sometimes the problem is just the mesh and not the solution options (GIGO stands true in CFD as well). It does however get easier with experience. The safe advice is the simplest one: when changing solution options doesn't help, refine mesh and run again.
Kind regards,
Theodore.…
se enseñan los principios de modelado básico y orgánico en Rhinoceros. En Grasshopper se estudian los principios de Parametrización, panelización y análisis en Grasshopper, así como el proceso de manufactura digital para maquinaria de corte Láser y CNC.
UN solo pago anticipado $5,000.00
Pagos diferidos $5,500.00*
*reserva tu lugar con el 50%
De lunes a viernes de 10 am a 18 pm
Del 23 al 27 de julio de 2012
DURACION: 40 HORAS
SESIONES: 5 DE 8 HORAS
o info@dimensiontallerdigital.com
informes al 55 (50 16 0634) con Mayri Gallegos (o al cel. 55 28 85 24 73)
Incluye material para corte digital.…
Horticulture and Landscape in same time.
The most common plastic materials used as agricultural films are the low density polyethylene (LDPE, with a density less than 0.93 kg m−3), the copolymer of ethylene and vinyl-acetate (EVA)
Also here you can find the characteristics of the flexible materials for greenhouse covers (adapted from CPA, 1992 and Tesi, 2001) as much as i get.
UV-PE Film ( UV-PE~ polyethylene Long life or UV)
Thickness (mm) = 0.18
Direct PAR transmissivity (%) = 90
Diffuse PAR transmissivity (%)= 86
Long-wave IR transmissivity (%)= 65
EVA Film ( EVA~Ethylene vinyl-acetate copolymer)
Thickness (mm) = 0.18
Direct PAR transmissivity (%) = 90
Diffuse PAR transmissivity (%)= 76
Long-wave IR transmissivity (%)= 27
and here you will find the global heat transfer coefficient’ (K in W m−2 °C−1) for the above greenhouse covering materials, measured under normalized conditions (temperatures: exterior: −10°C, interior: +20°C, wind: 4 m s−1). (Source: Nisen and Deltour, 1986.)
Cover Clear sky Overcast Sky
Single PE 8.8-9.0 7.1- 7.2
Single EVA 7.8 6.6
Note : the PAR radiation (photosynthetically active or photoactive radiation and its the amounts to 45–50% of the global radiation; Berninger, 1989)
The name PAR is used to designate the radiation with wavelengths useful for plant photosynthesis. It is accepted that the PAR radiation ranges from 400 to 700 nm (McCree, 1972), although some authors consider the PAR from 350 to 850 nm.
The composition of the radiation changes with time, as a function of the Sun’s elevation and the cloudiness. When the Sun is low over the horizon, the short wavelengths are reduced (less UV and more red). The clouds reduce the amount of energy, greatly decreasing the NIR.
The PAR proportion in relation to the global radiation increases with scattering (diffusion). It is lower with clear sky and in the summer (45–48%).
kind regards
rafat …
Grasshopper. So, I once made an attempt to bind ms sqlServer in order to get frozen definitions at some states, to avoid managing baked objects in Rhino and also be able to retain whole results without using the GH state manager that rebuilds everything.
But at that time GH's VB.Net component didn't properly read referenced dlls and I forgot it since then.
At first, I was surprised by Slingshot's extensive interface : I was still having in mind my own old project, a tool that would have acted at the Rhino's geometry object level, and auto creating the needed tables.
The bd would have consisted of a main table, owning the objects ID and name, and related tables containing the necessary information relative to the main objects.
For example, a Brep is made of so and so underlying objects, passed to respective tables, according to GH objects definition layout (just the way they are written in the xml schema).
Then, on a db, query an object by name, and retrieve the whole object or underlying objects (e.g. at the bounding curves level, or points level for a Brep).
With Slingshot, I made a few attempts to cheat GH with BLOB data fields, but no way to get a whole object. It seems that GH simply provides an object.toString ... and GH is definitely not conceived to produce persistence outside of Rhino. If I have some spare time, I will try to extract
About points and colors, I am now simply using a single field with CHAR(asLargeAsNeeded...), as GH parses String to every Point (or Vector or Color) entry of any component.
I do so because it need less to display on the canvas...
Whatever I wrote before, I really like your conception, as opened to relational interactions between ...whatever you need or dream of !
One last thing : GH can't open the definition file "Genome_DB_Template.gh" that I've downloaded from your site : http://slingshot-dev.wikidot.com/database-genome. I was expecting to learn a lot from your very smart stuff ! (I am running GH 08.00.13 and Slingshot 0.7.2.0)
Slingshot is running great, opened to any use...Thanks again.
Best,
Stan
…
on 2: I think the reason to draw a fitness landscape is to highlight graphically the presence of local minima, even in a simple optimisation problem. In architectural terms, this means getting an idea of how many sub-optimal solutions there are in a problem, which helps while exploring conceptual design proposals.
Have a look at this very basic example (which I published with two colleagues on "Shell Structures for Architecture", chapter 18): a shell footbridge (24m x 4m footprint), which is generated by two parabolic section curves (the two apex heights are the two design variables). The maximum displacement of the structure under gravity load and self-weight is the objective function. Simple example, but several local minima and interesting shell forms (image below).
@AB,
The expression used by David in the Number of Samples Input is a simple “x+1”. By grafting the Divide Curve Output, he got 81*81 lenghts (6,561 values). You have to make sure that number is divisible by the no. of samples. The second expression used for the Length output is only a scaling factor (my guess), to control the height of the fitness landscape drawing.
Cheers…
n account of the position of the sun and weather cannot be expressed in terms of a single set of luminous intensity values (which is what IES files do).
With regards to your example files, I agree with Chris. The primary reason for the low illuminance levels is that the light bounces are getting lost in the tube. Have you checked with the manufacturer/distributor if the location of the IES file should be inside the tube and not flush with the ceiling? Physically modelling such tubes in lighting software like Radiance (which is what HB uses) or AGI32 is a fairly expensive proposition. This is one of the reasons why manufacturers provide photometric data for such devices (however simplistic that data might be).
The candelamultiplier increases or decreases the luminous intensity values. So it will have a direct impact on the calculation. The primary reason for having that input was to enable users to do some testing with different lamp types and environmental factors such as dirt depreciation. You need not change them for your simulation. Assuming that the IES file is inside the tube, in order to make this calculation work inside HB you'd have to crank up the calculation settings to a very high level (start with -ab 10 -ad 4096).
Finally, due to shortcomings in the annual simulation software (Daysim), IES files will not work directly work with annual calculations. However, there is a fairly easy workaround for that issue. In case you are planning to run annual calculations with IES files, please let us know here.
Sarith…
ing illuminance and limiting exposure (lux hours). Hours with direct solar irradiance are likely to exceed the limiting illuminance thresholds, which range from (200 to 50 lux as per Table 3.4 in CIE 157:2004). It makes sense to consider direct illuminance (an ab=0 simulation in Honeybee) separately from a normal illuminance calculation.
Assuming that the museum exhibits have low to high responsivity to light, an ideal solution would minimize direct sunlight. For daylight from the sky and reflected light, it might be enough to keep the illuminance levels below the recommended thresholds and then sum up lux-hours.
Daysim, the annual daylighting engine used by Honeybee and DIVA, is not very accurate for direct-sun calculations. You will get more accurate results if you run your analysis with Radiance directly.
Instead of considering the horizontal illuminance grids, one can create grids that correspond to the dimensions of the exhibit and then average those values. I think single points, as shown in your gh file might not suffice. Calculating lux-hours is by far the simplest part of such a simulation. It will only require averaging these points, extracting them into an array and then summing up that array.…