algorithmic modeling for Rhino


Pachyderm Acoustic

Pachyderm is a plugin largely used by Designers and Scientists alike to simulate acoustics in buildings, rooms, cities, and other settings.

Location: Earth
Members: 179
Latest Activity: Oct 24

Hello Pachyderm Users,
We are going through an exciting period, including the startup of an organization to support the growth of Pachyderm, and extend the educational agenda of the project. In the next few weeks, we will be submitting our long-form 501(c)3 application, which will give us the rights of a not-for-profit organization established in the state of Connecticut. As part of the transition, we are phasing out the old website. The new site will be up in the next few weeks, and you can find it at:
We are looking forward to the next phase of this project, and we hope that you will be there with us to learn and continue to support us!
kind regards,
Arthur van der Harten
Executive Director
Open Research in Acoustical Science and Education

Discussion Forum

Particles colour in simulation 2 Replies

Hello everyone!I set the particles to downgrade from red at the beggining (a hot colour) to blue at the end (a cold colour), but when I run the simulation some of the first frames turns from red to a…Continue

Started by Catherine Granada. Last reply by Catherine Granada Oct 24.

Absorption designer 1 Reply

Hello everyone. I am trying to get the absorption coefficient of an element with the "Call absorption designer" in PachyDerm_Acoustic - Pachyderm Hybrid Models. When I set a Porous material + Solid…Continue

Started by Catherine Granada. Last reply by Arthur van der Harten Oct 12.

Installation issues 48 Replies

This is a place to ask qustions about installation. Please post your questions here and I will get to them as quickly as I can.Continue

Started by Arthur van der Harten. Last reply by Arthur van der Harten Apr 19.

Sound Simulation_ Reverberation Time calculation_Inconsistant Results

Good morning all,I am currently working on the calculation of the reverberation time of different closed spaces. I have a closed geometry (simplified model of the Hypogeum in Malta), and what I did…Continue

Started by Alejandro Estrella Apr 1.

Comment Wall


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Comment by Arthur van der Harten on September 21, 2023 at 5:31am

Hi Catherine,

You change it in the usual way. It's just a list of 8 numbers. The default is 120 dB at each of the 8 octave bands, 63 Hz. through 8kHz.

You can either right-click it and mouse down to 'Set Multiple Numbers'. You can also use a number module, and set 8 numbers in it, and then connect it to the 'P' input.

Hope this helps.


Comment by Catherine Granada on September 20, 2023 at 3:19pm

Hello Arthur, 

I would like to know please how can I change the sound power of my source in Grasshopper, wich is set in 120dB if I am not wrong. Or, is it possible to change that parameter?

Thank you in advance!


Comment by Encarni Encinas on April 19, 2023 at 1:30am

Hi All,

I have been trying to add the Pachyderm Acoustics plugin for both Rhino 6 SR10 and Rhino 7 SR19. For both programs I get the loading error when trying to add the plugin, and I don't know why or what I can do to fix it. 

If anyone has any hints on how to fix it, it would be of great help to me.
Thanks in advance :)


Comment by Arthur van der Harten on March 24, 2023 at 12:41pm
Hi Catherine,
You set materials in the materials tab via absorption and scattering coefficient... Although it isn't the right tool to predict sound isolation.
Comment by Catherine Granada on March 24, 2023 at 12:30pm

Hi Arthur,

How can I set the different materials that i'm working with in my simmulation? For example, I want to separate a space with dividing panels wich have different geometries and materials (wood, glass, metal, plastic) and want to see how the sound behaves in each case. Is it possible to do that?

Thank you in advance.

Comment by Daniel Horta on December 7, 2022 at 12:16pm

Hi Arthur, it's me again... sorry haha!

I was having a problem that every time I would try to convolve some IR given by a simulation I would notice a very distinct separation almost like a pre-delay that I thought didn't make sense for the space I've simulated. 

So I checked the IR .wav file and found this:

This big gap at the beginning is normal? Why so? When I convolve the IR without this gap the auralization sounds much more credible.

Thank you!

Comment by Kyujin on December 5, 2022 at 5:20am

Hi Arthur, 

After running the simulation, I'm trying to analyze what the results imply. Is there a way where you can get the data of rays that were taken into account for calculation? The simulation was done with trace specified number of rays. If it's possible in Rhino instead of grasshopper, it would still be a great help to know. Thanks:)


Comment by Daniel Horta on December 1, 2022 at 8:24pm

Thank you very much for the super fast reply, Arthur!!

I really appreciate not just the incredible software that you offer completely for free but also your dedication to the education surrounding it and acoustics in general. 

Coming from an education in Architecture at a school that doesn't offer extensive education in acoustics people like you make the process of understanding these complicated concepts way easier and enjoyable



Comment by Arthur van der Harten on December 1, 2022 at 5:57pm

Hi Daniel,

I haven't heard from you in a while. Welcome back!

Some time ago, I added Echo Kriterion, which was difficult because I don't speak German. Happily, my friends at Politecnico di Torino worked through their network to get a colleague to translate it for me, and that translation is what Pachyderm's implementation is based on.

Yes - Echo Kriterion is based on the paper by Dietsch and Kraak. They made a few assumptions about echoes, and came up with a means for processing the impulse response so that you can get an idea of whether sound at any time exceeds a certain threshold that may correlate with perception of echo. It is empirical in nature, which means they tested some examples on a cohort of individuals, and decided on that basis that at some value, 50% of people will hear an echo for speech or music, respectively, and then decided on another value at which 10% of people would hear an echo. True or false answers the question "Will XX% of people hear an echo if speech/music is heard at this location?" True = yes. False = no.

Now - how accurate is it? I did not modify the implementation from what was specified in the paper, but I wouldn't trust the results outright. The study had a relatively small sample size (as most papers in acoustics do, usually) and I bet the method could use further review, verification, and perhaps some fine-tuning or improvement.

Here is how I use it - if it says True, there probably is an echo... however, if it says False, that doesn't mean there isn't one.


Comment by Daniel Horta on December 1, 2022 at 5:18pm

Hi Arthur, hope everything is fine.

I was reading the work from Lovstad about Echo Criteria trying to understand how the concept from Dietsch and Kraak is implemented in Pachyderm. 

I have to be honest and say that I don't have the necessary knowledge to fully understand the text yet. So I would love some explanation about the Echo Criterion Parameter of analysis in Pachyderm. How should I interpret it and what it means to the acoustical qualities of the space score "false" or "true" in this criterion?

Thank you in advance, cheers. 


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