Thanks to Professor Isak Worre Foged, for putting together this set of videos on acoustics, and Pachyderm tutorials. You can find them here.

Questions and comments about the videos should be directed to This email address is being protected from spambots. You need JavaScript enabled to view it..

As always, questions about Pachyderm should come to This email address is being protected from spambots. You need JavaScript enabled to view it.

After 3 years, I have the source code posted to Github. This includes not only my work-in-progress code from the Rhino plugin and Hare library, but also the code for the elusive Grasshopper plugin. With this, I announce the release candidate period for Pachyderm 2.0.

There are many new features - far too many for me to name... a lot has happened in three years, and Pachyderm has grown with me. However, I am hoping that it's growth can be accelerated by benefiting from the growth of others as well, which is why the code is no longer under lock and key (a rather timid approach to open source which I am entire responsible for), but freely available on Github. It is my hope that those of you who are as interested in acoustics and design in simulation will come forward and contribute.  (I know you're out there... you emailed me just the other week. Come on... you know you want to!)

All repositories can be found here: 

A few caveats if you download it just to use it - this is far from a finished product. At a certain point, you realize that if you keep postponing publication just to resolve all of the experimental implementations of the project it will never reach the outside world. The core functionality is solid, but here is a list of a few things to be cautious about when using:

- Absorption coefficient calculation - this works great for Equivalent fluid models and finite samples, but the other models will throw an error or crash, (because they are unfinished.) Please explore it, but be careful.

- Finite Difference Time Domain - oh where do I begin... this very enticing technique is brilliant in its simplicity, and confounding in its limitations. I have opted to use a fourth order accurate scheme (27 point 3d stencil) however, this has proven problematic, as the model will not always successfully build. If it is unsuccessful, there will be red and blue boxes where the model was unable to resolve the boundary condition. Should you choose to run it with one of these, the program will crash. There is usually a configuration which will run, but finding it requies fiddling with the max frequency and placement of the model. Additionally, it is solely for visualization at this time (until I or someone else can find a way to make its use practical).

- Edge Diffraction - This version includes Biot Tolstoy Medwin edge diffraction according to the brilliant work done by Peter Svensson, Paul Calamia and others. The implementation seems solid and quick for first order, and the output looks plausible, but has not been benchmarked. Higher orders are not implemented yet.

- Surface Sources - This works, but initial power is wrong, which means that for now, I do not recommend using it. Line sources and point sources work fine.

- Auralization has moved to its own control. You start by picking which interface you would like to pull results from to create an auralization, and then setting the channel configuration and dry signal. I think there are still a few crash-bugs in it, so please let me know if you find one.

That's all I can think of for now, so have fun, and if you find anything else that is worth asking me about, please do. You know where to find me. (I don't bite. Please let me know.)

It looks like the images did not transfer over when I upgraded the site. My apologies for that. I will try to get them back, but it may be a few weeks. If it turns out that I can't, then I will post new ones when I have v2.0 benchmarked.

For those of you who mentioned the benchmarks in particular, the images were posted there for years, and my seasoned users know how well v 1.0 benchmarked. I promise that this is no deception on my part - It is just one of the hickups associated with a site upgrade.

All the best,


Welcome! Due to recent repeated attacks on the site, I had to destroy the old Joomla site and create a newer more up-to-date site. I hope you like it.

Pachyderm is very much alive and well as a project. In fact, more and more interested parties have come forward recently, just as the new 2.0 release nears completion. The new version will have pressure based algorithms, edge diffraction, loudspeakers (clf), calculation of more precise surface properties, new visualization tools, a grasshopper extension, and many other new possibilities. I look forward to continue working with you to improve awareness of acoustics issues in the built environment, and to further the art and science of acoustics simulation.

kind regards,