Questions about Pachyderm options

Hallo dear Arthur, thanks for your job and passion.

I finally managed to test Pachyderm and I have a few question:

REVERBERATION TIME: knowing the volume and the m² of the surfaces of the geometry from the Rhino model and having the absorption coefficients of the materials that are entered into Pachyderm, why is it not possible to generate a reverberation time diagram, without the need to start any analysis?
MAPPING METHOD: When for example the mapping of the Strenght Index (G) is generated through the "create map" option, succesively I can´t generate any other energy criterion map, but I have to redo the simulation.

Is it a limitation of the software or am I wrong something?

MAPPING METHOD: I kindly wanted to ask what is the difference between minimum and detailed convergence and why the number of reflections order it takes into account for the simulation is not specified. The mapping method take care only of the Raytracing Method or the Image Source too?
MAPPING METHOD: Why is the mapping value that can be exported to Rhino not generated for all the calculation raster points, but maximal only for 100 values?
MAPPING METHOD: This method hasn't been implemented in Grasshopper yet, has it?
RAYTRACING METHOD (Pach:RT): I did a raytracing through the components of GH, using only the Pach_RT, and I had these curious results in terms of time:

RaysCount: 15.000, IS_Order:1 = 5min

RaysCount: 15.000, IS_Order:2 = 12min
RaysCount: 15.000, IS_Order:3 = 3min
RaysCount: 15.000, IS_Order:4 = 8min
RaysCount: 15.000, IS_Order:5 = 3min

Why a raytracing with only 2 order, is more and more extensive than the 3/4 and 5 order?

ANALYSIS RESULT: Would there be a way to export all the results of a simulation, as is done via Odeon, to a .txt list?

I apologize in advance for asking so many questions, I hope you can find the time to answer,

Yours sincerely from Müller-BBM

Replies to This Discussion

Permalink Reply by Arthur van der Harten on September 2, 2021 at 12:45pm

Hi there, G.C. Thanks for the kind words. I'll do my best to answer your questions.

Reverberation Time - do you mean using the Sabine or Eyring equations. As a collaboration with Alban Bassuet, I did add this, but I don't think its part of the public release. The method it uses is as old as the first commit, though. You can probably access it using a python script if you want to.

Mapping Method 1 - I think you may have been deterred by the fact that the map is a mesh object in Rhino. Just select it and move it. You'll then be able to see the next one you plot.

Mapping Method 2 - The mapping method in Rhino does not use image source - only ray-tracing. I've thought of adding image source to it, but for certain things it will probably be very time consuming to do, with little actual benefit. I might certainly consider adding the option, if you/people feel strongly about it.

Mapping Method 3 - So the tool in Rhino to plot the values out on the map only does it at intervals, because it gets very crowded very fast. I found it easier to read this way. Maybe there should be more controls on it, though. Let me think about that.

Raytracing Method GH - I think I would need to know more about your grasshopper script and the model you are working on to answer that. However, you should know, the IS_Order in Raytracing is only informational to the Ray-tracing method. It doesn't do image source - that's done by the Image Source Component. The ray-tracing method needs to know how many orders of image source you ran so that it can omit those specular reflections up to that order. This way, when you add the image source to the ray-traced result, you aren't counting anything twice.

Analysis Result - in the rhino version (Pach_Hybrid_Method) check out the file menu at the top. There are several ways to export the results of your simulation to a text file. There are many other ways to parse the info, but some basic stuff can be had in a text file.

Thanks for your interest. Let me know if you have additional questions.

Arthur

Permalink Reply by G.C.Ruvio on September 3, 2021 at 8:33am

Hallo Dear Arthur,

thank you,vvery kind to answer so quickly. Thanks for your time.

REVERBERATION TIME: Yes sorry, I was referring to estimate the RT according to Sabine or Eyring method, to have already a good starting point, without start any simulation.

I don´t understand what you mean with access through a Python script.

MAPPING METHOD 1: Yes, I saw that it creates the mesh, but now I have checked more in detail and it makes me export only the SPL, SPL (A Weighted) and the Strength/Loudness. Tested on 2 different computers. Potentially looks like a bug.

MAPPING METHOD 2: Thanks, good to know, but basically with how many reflections order analyze the raytracing method?

MAPPING METHOD 2: Thanks, good to know.

RAYTRACING METHOD: Thanks for the advice.

ANALYSIS RESULT: thank you, I didn't notice. I noticed that the exported values have 14 decimal numbers beyond the comma, would it not be more readable to round to only 2 numbers?

New Question:

ISO COMPLIANT: why when I have for example as a result of + 16dB for the C80 criterion in a given receiver, it tells ISO Compliant: YES, if the standard ISO 3382-1:2009-10 gives as margin for clarity from -5 to + 5dB?

Thanks in advance

Permalink Reply by Arthur van der Harten on September 3, 2021 at 10:07am

Hey there,

Reverb time: the code to do a Sabine/Eyring calc is in the version you have. You would need to use Rhino's built-in scripting engine (which uses IronPython) to access it. Otherwise, you can wait until I'm satisfied with my new version, and it will be in a grasshopper component at that time.

Mapping Method 1: I'm not aware of this issue. It certainly isn't an issue in the version I'm using, but I'll see what I can do.

Analysis Result: I like to err on the side of giving you more information, rather than less. The text file is meant to be imported in Excel (use semicolon (I think) delimitation to divide everything by cells. You can then set it to view it at 2 decimal places yourself.

ISO Compliant: The result may not be compliant with the recommended range for your use, but the software doesn't even really know what you are simulating to begin with. ISO Compliance states that the calculation is being done in an ISO Compliant manner. So, for example, you are using one source, and not 2 to calculate the parameters.

Arthur

Permalink Reply by G.C.Ruvio on September 6, 2021 at 12:02am

Hello dear Arthur,

Reverb. Time: I don't have the knowledge to be able to do what you explained to me. I will gladly wait for your next release.

Mapping Method 1: I recorded a little video to show you what happened.

https://fspit2storage.blob.core.windows.net/fspwinappblobs/20210906...

Analysis result & ISO compliant: thanks for the explanation.

One more question about the mapping method: Togheter with the map, would there be a way to get the average results of the various energy criterion, divided by frequencies?

Thanks and greetings

Permalink Reply by G.C.Ruvio on October 1, 2021 at 8:57am

dear @Arthur I come back to disturb you.

I would ask, why when I have set multiple points in the StationeryReceiver component, in the Raytracing (PachRT) analyzed each recs, but the ImageSource (PachIS) component, generate the raytracing path from Source to receiver only for 1 "Sensor"?

Would be optimal to be able to analyze, for example, all the sensors in the room, even with the PachIS, because I found that only with the PachRT + PachIS combination I can have a comparison similar 1 to 1 with a Odeon simulation.

Thanks and best regard

Permalink Reply by Arthur van der Harten on October 1, 2021 at 9:29am

Hi again,

I think the grasshopper component is only showing you the one (more a novelty than a practical or important thing). You can rest assured that if it put a receiver that really has all the receiver points in it, the image source method did the calculation for all of them.

I recently had to compare Pachyderm to CATT for another project. The results were interesting. I would be interested in your comparison if you can share sometime (offline, of course). Please feel free to email me at info@orase.org.

Arthur

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