ted a picture of in your post. The reason is that sound has larger wavelengths than light.
With a light rendering model, energy can be said to reflect specularly, relative to their geometry, because the wavelength of light is inifinitesimally small relative to any object you might have modelled. With sound, energy may travel and reflect diffusely, or move around objects, depending on the scale of those objects. Think of the fundamental equation of frequency to wavelength - speed of sound = frequency X wavelength. Using that, you can see that a wave in the 125 hz octave is about as tall as a human being (or maybe a little taller) and would easily move around your body, not being reflected at all. A wave in the 1000 Hz. octave band is as big as your forearm, and might reflect specularly from your torso. A wave in the 4000 hz. octave band is about as long as your index finger, and might reflect off of your torso, or even your head.
Similarly, if you were to model the seats explicitly, it might be relatively accurate at very high frequencies (say 4000 hz. and above) but that is a very small part of the answer. Consensus in the field is that the most accurate way to model the seats is with a flat plane, raised to about shoulder height, and then with scattering coefficients applied to represent the varying effects of geometry on sound. I tend to use low coefficents below 250 hz. (say around 30%) and high coefficents above 250 Hz.(90%).
Absorption depends on the seat which was chosen. This is often a good area to use for a model calibration based on measured reverberation time.
Arthur…
ces are distorted (second). What is going on?
Surfaces in the second are a rhino cage edit of the surfaces in the first image. They were originally all closed polysrfs exploded just to input into grasshopper.
In the definition attached, each surface is compared to an original (its the small box in the far left of the top image) The point there is the ability to select for more than just the 6 faces of a cube, but find the closest match to more complicated inputs. In the second image, distorted surfaces are being compared to a distorted original.
If I have my math right, two parallel unitized normal vectors should have a dot product of 1, and the further away from 1 their dot product the further away from parallel, no? Why does it fail when I leave the comfy land of 90 degrees?…
Added by Peter Stone at 2:39pm on January 28, 2015
e to constrains, I HAVE to do it like this (I can't 3D print everything or opposite).
First
I have no idea how to make the panels, without so many duplicate Edges, Faces etc.
Second
I can't figure out how to align the triangle panels to fit in the construction, so it can be assembled ideally without glue. This problem is both conceptual (I can't figure out how to do it fiscally) and grasshoper-wise - I don't know how to organize data list and produce a global movement, so that the triangle parts do not intersect with each other, BUT intersect the 3d printed construction part (where they fit fix in or just fit and can be glued).
Triangles will be milled out from 3mm Plexiglas, BUT I will not have an option to mill at an angle, so only 90° edges.
3D printed parts will be executed by a high level production powder printer, so it should hold good.
Any ideas?
best,
cuki
…
File) 2. I have designed a curved Trichordal-Truss from one curve in Rhino.
The Truss is lying in the XY direction and the footer is placed on the zero point.
3. And now my problem:
I want to put the Truss-object on the feet, move 90°
(from the XY axis to Z axis, see sketch 1).
4. Then copy / move the truss to all 36-points of ellipse (see sketch 1).
5. Align the 36 trusses with the center of the triangle .
pointing at the center of the ellipse (see sketch 2).
6. Using a slider to change the position of the 36-Trusses at der ellipse.
Variable distance between Truss and ellipse (see sketch 3).
Thanks for you Answer.
Best regards
Noureddine…
multiply of variants from Galapagos, to have a chance for better analysis and comparability after. I also would like to use more then one solution in my design after.
In old topics i found kind of 3 solutions.
1.Change Galapagos to octopus ( what don t really want to do, i am kind of happy with Galapagos)
2. Use Slingshot! and MySQL Database ( it s look a little bit too complicated from the first view)
3. Use Colibri and Design Explorer Platform (looks kind of pretty way to solve my problem)
So i tried to add Colibri components to my definition , but have some mistake in the Colibri Aggregator after adding the Genome "An item with the same key already been added". I think it comes because for some steps i am using the "Gen Pool" and not a normal slider. Is it a way to connect Gen Pool and Colibri (i really prefer to have it, then a lot of sliders in some cases)?
And the second question (if i will get it solved with gen pool), could i somehow controll the recording process? For example i would likte to record only variants wit fitness over 90% or start recording just after 20. generation and record till the end?
I also opend for all other possibilities to reach the same goal (record/save/bake multiply variants from galapagos)
…
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…
r "virtual partitions" as follows:
What I mean "air walls" here, is derived from the description of the E+ documentation with the header of "Air wall, Open air connection between zones". (Page 17, http://apps1.eere.energy.gov/buildings/energyplus/pdfs/tips_and_tricks_using_energyplus.pdf)
As I understand, the term "air wall" used in E+ here refers to a description of something like "boundary condition" between adjacent interzone heat transfer surfaces, but not a kind of "construction or material" (like air space resistance or air gaps within a wall/double glazing window).
The main purpose of introducing the "air wall", is to simulate or approximate the airflow/convection/natural ventilation effect between multiple thermal zones which are connected by a large opening.
In my previous tests, using HBzones and GB, I managed to create the gbXML file which can be successfully imported to DB (without assigning any constructions within HB). And the adjacency condition can be recognized automatically by DB, even when I did not use the "Solve adjacencies" component in HB - shared surfaces between multiple thermal zones are recognized automatically by BD as "internal - partition"(which are standard partitions, but not virtual partitions).
In order to create/approximate "virtual partition", I need to manually draw a "hole" in the standard partition surface (fig.1&2). Again, the reason why we want to use "virtual partitions"(or "air wall") is that it allows airflow between multiple thermal zones which are connected by large openings and we could get different temperature of the each subdivided thermal zone which compose a large thermal zone.
My question is, if there is a possible way to simulate/approximate this kind of "virtual partitions"(or "air wall") in HBzones or in GB? If so, I would like to test if DB recognizes it or not. Actually, we expect that there is no need to involve any manual operations (like drawing a "hole" in the standard partition surface) in DB, due to an automatic optimization loop.
Thank you!
Best,
Ding
fig.1
fig.2
…
d the fact that one pipe goes out and one goes in, that the surface normal direction is opposite for the two surfaces? Based on an earlier thread, you should know why by now. The two curves have opposite directions (again!); see the white arrows using Rhino 'Analyze | Direction'?
As before, you can fix that by flipping one curve to match the other. HOWEVER, you connected your curves directly to the 'Divide' components instead of using 'Crv' geometry params - bad form. And as before, you "fixed it" by reversing the list of starting points ('S' input to 'BiArc'). Better like this - 'Crv' params are internalized, no need for Rhino file:
Well, well! That didn't fix the opposite surface normals after all! Trust me, though, using geometry params and being conscious about matching curve directions is "best practice". But I haven't lofted 'BiArc' curves for awhile, it's late and I want to move on. OH! I just noticed that you reversed the 'Z' direction for one half of the 'BiArc' - that explains it:
Moving on... You've basically got it, though I would do it differently - same result, like this:
I haven't really explained surface normal vectors - can you figure it out from here? One more little wrinkle (Normal_2017Mar17b.gh):
…
Added by Joseph Oster at 12:03am on March 18, 2017
ported to Rhino and "set" in Grasshopper, i trim both surfaces from their rectangular bases so that when sDivide is used it creates and distributes the same number of points on each surface.But heres the problems: a) if i use the "trimmed" surfaces with SrfGrid it errors warning: "A point in the grid is null. fitting operation aborted".I'd learned this was caused by "nulls" replacing position Data Items when the rectangular grid(surface base) was trimmed away. So i used Clean Tree which worked removing all nulls, then Shift Paths\Flip Matrix to create line-endpoint pairs for Polyline\Evaluate Curve. I Flattened the last Flip Matrix placing all data items in one source for SrfGrid, like in the working Untrim\CopyTrim definition.This time,.b) SrfGrid errored with: "The UCount value is not valid for this amount of points",.So, i substituted a 356 value, numeric Slider in the Addition B param., and tested its range until a valid UCount was found. Then SrfGrid fitted a surface thru the points, BUT,d) those SrfGrid surfaces are extremely deformed even thought the points preceding it from Evaluate Curve are accurate,SEE: def: "3b-RGH_SurfaceBlend.gh",AND,.a2) if i use Untrim with CopyTrim then SrfGrid works, but since the Jokers limbs WILL be in different surface positions then the blends between the Arm (for example) will rise from its relative FLAT position on the untrimmed Source surface to the Arm on the Target surface, rather than morphing from the Corresponding Arm position on the Source surface,. ..see def.: "4-RGH_SurfaceBlend.gh"So please let me know,..1) how to produce accurate surfaces from SrfGrid in def.: "3b-RGH_SurfaceBlend.gh",. ..(NOTE: BOTH these def's contain 2 indentical, "internalized" surfaces, but if def. 3b can be made to work it will also work with Dis-similar surfaces)2) which component to use or how else to determine the correct UCount value for a specified amount of points(ie:155), re: SrfGrid error: "The UCount value is not valid for this amount of points",.3) how else to force SrfGrid to work with Trimmed surfaces?, AND,..4) how to force intersurface, point-blend correspondence lines: Polylines(PLine) to be connected between correctly! correponding positions (Limbs) on the surfaces?,
Really! appreciate all help, definitions and kind generosity common to this knowledgable membership,
Cheers!,
Jeff…
50 and reduced the 'cell size' slider to 0.5. When the 'Azimuth' angle is changed to 180 +- 90 (dawn or dusk), the points are widely dispersed, reducing the density and increasing the number of cells in the "sparse grid". Under these conditions, the number of cells was ~2000 and the Profiler time for 'Boundary' went up to a full minute or more each time 'Altitude' or 'Azimuth' was changed.
So I created this code to benchmark some alternatives and found two interesting things:
'Boundary' surface performance (v.1) is not linear. As the number of surfaces goes from 1000 to 2000, the time per surface goes up dramatically.
I tried three alternatives for creating a rectangular surface at a given point that are all substantially faster: v.2, v.3 and v.4. For 2000 points, v.4 is 150 times faster than v.1 !!!
Performance of v.2, v.3 and v.4 are similar and all scale up very well. To benchmark beyond 2000 points, I recommend disabling the VERY SLOW v.1. At 5000 points the 'Pop2D' component takes ~11.3 seconds but v.3 and v.4 take less than one second to generate 5000 surfaces!
See boundary_2015Nov19a.gh attached.
So I replaced the 'Rectangle' and 'Boundary' components in my sun reflection model with v.4 in focus_2015Nov19b.gh (also attached) and the performance is amazing.
I'm sure someone has mentioned this performance issue with 'Boundary' on the forum before but as with many things, I didn't realize what a major obstacle it can be until I discovered this for myself.…
Added by Joseph Oster at 9:16pm on November 19, 2015