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: 161
Latest Activity: Jun 18

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

Some newbie issues 11 Replies

Hi all,I'm learning how to use Pachyderm.I create a testing model with Source as Women Whispered.I use Plywood wall material in Library.But the Sound Pressure Level seems too high. I don't know what…Continue

Started by Thai Le. Last reply by Thai Le Apr 26.

Running pachyderm with Hops 1 Reply

Has anyone been able to get Pachyderm to run with Hops?We are having some troubles and it seems like Hops can speed up the heaviest part of our script.See also…Continue

Started by Kevin Hinz. Last reply by Arthur van der Harten Apr 24.

False Colour Mesh Mapping in GH 1 Reply

Hey all - I'm having trouble getting the False Colour Mesh Mapping component to work in GH. I have created the false color in the rhino workspace through the Pachyderm plugin, but not in GH.My GH…Continue

Started by Hugh Soward. Last reply by Arthur van der Harten Apr 24.

Material selection disappeared 3 Replies

Hi all,After I pressed Create Smart Material, the window go like this. Material selection area has disappeared and there is no way to change the Material for this layer again. Please help.…Continue

Started by Thai Le. Last reply by Arthur van der Harten Apr 24.

Comment Wall


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Comment by Arthur van der Harten on June 5, 2022 at 6:10pm
The selected color scale works with the 'preview' option. If you use the buttons at the bottom of the form, it uses actual geometry, which does use the current layer.

Variegation allows you to select a characteristic dimension for the surface scattering or roughness. This might be the depth of relief, or have something to do with the size of flat portions. That dimension is the quarter wavelength of above which scatterering is very high, and below which it is very low.

Convergence - minimum convergence takes portions of the impulse response and determines how much it has changed at intervals. When the degree of change is below a certain threshold for 10 consecutive checks, then the simulation can be said to have converged sufficiently.

Let me know if you have questions.

Comment by Daniel Horta on June 5, 2022 at 3:45pm

Furthermore, I would like some insights into how convergence works in Pachyderm. I'm familiarized with the concept of convergence from CFD simulations but it seems to work differently in Pachyderm. Besides that, what we can do to correct a model that doesn't seem to converge when put through "Detailed Convergence". Thank you!

Comment by Daniel Horta on June 5, 2022 at 3:32pm

Hi Arthur, hope everything is fine.

I was wondering if you could explain how we should use the "Variegation (characteristic dimension)" slider. I searched online but didn't manage to find anything about this specific term in articles about the use of scattering coefficients in simulations. Thanks in advance. Cheers!

Comment by Robin Richardson on March 15, 2022 at 7:37am

Hi all, hope you are well.

I'm new to using Pachyderm and could use some assistance—when using the Particle Animation part of the Rhino plugin, the simulated particles don't appear to use the selected color scale—instead taking on the color of the currently selected layer. This only happens in the screen captures saved by using the Animate button; the particles are colored correctly in the viewport when using the Preview button.

Advice? I'm running Rhino 6 Windows.

Comment by Arthur van der Harten on February 15, 2022 at 12:51pm

Hi Jimmy,

Good of you to notice, and scrutinize the results. The version you are using doesn't accomodate noise barriers very well. What it needs is an acoustic screen calculation. I've been working on one, but it's not quite ready yet. However, email me if you'd like to play with it anyhow.


Comment by Jimmy Pristudor on February 15, 2022 at 9:51am

Hi all!

I am quite new to pachyderm, and hope that you could help me out with my thesis project. I am trying to set up a relatively simple simulation for a road side noise barrier.

I am using 'visualising pachyderm rays', and converting them into cloud particles later. I use a point to generate vertors from (vector star).

If I do not create a closed off Room, only the rays that actually hit something (the floor or the barrier) will be shown. Not the rays that move towards the sky.

If I create a closed box, I get closer to what I want. But the rays will bounce down from the 'sky'.

I have tried to make the irrelevant room surfaces (sides and upper surface) 'terminating surfaces' in the PachVisRays, but this did not change anything. I assumed this would terminate any ray that hits this surface...

I'd love to hear from you! Cheers!

Comment by Arthur van der Harten on January 16, 2022 at 7:56am
Thanks so much for sharing that. I didn't even know that video existed. It's fun to see people experiment... That said, I don't recommend his approach. You bypass a lot of Pachyderm's most valuable functionality doing what he did.

For example, did you know that using the animation tool in the rhino interface, the particles share energy with nearby particles, making it easier to visually detect things like focusing? Additionally, nowhere in his script due it account for surface absorption.

Furthermore, he is using a geometrical model of a diffuser to stimulate scattering explicitly. That's not the way it should be done. That might be somewhat accurate for extremely high frequencies, but in real life, the very large wavelengths of sound also influence the movement of sound energy.

There is a tool in the finite volume method section of Pachyderm that can be used to stimulate that more accurately.

I'm not sure why your result is different, but like I said, ORASE had nothing to do with the creation of that video, so it's not so easy for me to help out with that one. I suggest you try the rhino interface instead. Type 'pachyderm_animation into the command prompt. There may be a tutorial about how to use it on the ORASE website too.

Comment by Arthur van der Harten on January 16, 2022 at 7:46am
Hi Ishita,
Sorry - I never saw your question. You can do a lot in Pachyderm, and it's difficult to answer such an open ended question. Why don't you try experimenting and coming back with more specific questions.
Comment by Vincent Dissaux on January 16, 2022 at 4:18am

Hi All, I'm trying to follow a youtube tutorial about acoustic simulation using Grasshopper and pachyderm ( this one ). As you can see at 25:00 of the tutorials every particle disappears, mine stay stuck on the last wall they hit.. If one of you guys has any advice about that I thank you in advance. 

Comment by Ishita Sahai on October 1, 2021 at 11:54pm
Hi, what all components of sound can be calculated in pachyderm? how can we calculate noise absorption?

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