CAELinux 2020: Linux for engineering

CAELinux is a distribution focused on computer-aided engineering (CAE) maintained by Joël Cugnoni. Designed with students and academics in mind, the distribution is loaded with open-source software that can be used to model everything from pig livers to airfoils. Cugnoni's latest release, CAELinux 2020, was made on August 11; readers with engineering interests may want to take a look.

CAELinux's first stable version was released in 2007 and was based on PCLinuxOS 2007. The distribution was created to make the GPL-licensed finite element analysis tool Salome-Meca easier to obtain. CAELinux 2020 is now the eighth release of the distribution, which is based on Xubuntu 18.04 LTS, and has expanded its focus over the years into an impressive array of open-source CAE-related tools.

The minimum requirements for CAELinux 2020 are a x86-64 platform with 4GB of RAM for "simple analysis." For professional use, the project recommends 8GB of RAM or more with a "modern AMD/NVidia graphic card." The entire distribution can be run from an 8GB USB memory drive, with the option to install it to disk (35GB minimum). For those users (like me) who wanted to run the distribution as a virtual machine, the project recommends the commercial VMware Player over the open-source VirtualBox project due to "some graphical limitations" of VirtualBox.

There are too many different software packages unique to the CAELinux distribution to cover them all in a single article. Since the distribution is built on top of Xubuntu, CAELinux comes with all of the standard tools available in the base distribution. In addition to the standard packages, however, CAELinux bundles CAE pre/post processors, CAD and CAM software, finite element solvers, computational fluid dynamics applications, circuit board design tools, biomedical image processing software, and a large array of programming language packages. A review of the release announcement provides a full list of the specific open-source projects available, including a few web-based tools that merely launch the included browser to the appropriate URL.

It would be impossible for me to claim familiarity with the full range of tools provided, but I was familiar with many. For example, FreeCAD has been written about at LWN, and CAMLab was used in our article on open-source CNC manufacturing. I have personally used other bundled packages like FlatCAM for isolation routing of homemade circuit boards and Cura to slice 3D models for printing. What was particularly neat about exploring the distribution was getting introduced to new open-source software that matched my interests. I discovered KiCad EDA's PCB Calculator utility (simple, but handy), and I am looking forward to checking out CAMotics as another CAM alternative for my CNC router.

Others are doing interesting things with CAELinux, as described in this research paper [PDF] by Kirana Kumara that was published in the International Journal of Advancements in Technology. The paper, entitled "Demonstrating the Usefulness of CAELinux for Computer Aided Engineering using an Example of the Three Dimensional Reconstruction of a Pig Liver", describes the process of taking a collection of computed tomography scan (CT scan) cross-section images of a pig liver and converting it into a three-dimensional model using tools in CAELinux 2018. The paper indicates Kumara used ImageJ to mirror and concatenate the original image collection. That data was then imported into ITK-SNAP, which is "used to segment structures in 3D medical images"; it produces a 3D model of the images provided from ImageJ. Unfortunately, CAELinux 2020 appears to have removed ITK-SNAP from its distribution and attempts to install binaries from the project didn't work due to an incompatibility with libpng. Still, interested readers may have more success building the tool from source code — or using CAELinux 2018 instead.

The testing of the distribution prior to release appears to be limited to the capabilities of Cugnoni alone, who wrote for the 2020 release:

In my review of CAELinux, it is worth mentioning that a handful of the distribution software packages did not work properly in testing. For example, the KiCAD EDA bitmap2component tool would not run for me at all. This tool is used to convert an image into a component for placement on a printed circuit board. Other packages, like JavaFoil, started with warnings about an incompatible version of Java but otherwise appeared functional. The issues seem mostly limited to the less mature, highly specialized projects; more mature projects like FreeCAD or LibreCAD ran without issue. Regardless, it would be nice if it could be reported that everything worked as expected in a distribution — especially for one that is specifically focused on these tools. In general, the distribution relies on Xubuntu for packages for the provided software; but that is not true for everything. From a security perspective, the distribution relies on Xubuntu for updates. I was able to find a bug tracker as part of the SourceForge hosting for the project, but it did not appear to be in active use.

To try out CAELinux 2020, the ISO can be obtained from the web site, though it is oddly broken into three separate segments compressed using 7-Zip. According to Cugnoni, a challenge for the 2020 release was that the base OS and software "have increased massively in size over the year", making it "nearly impossible to do something really complete within the 4Gb file size limit for regular ISO images." Overcoming this limitation was a significant effort, according to Cugnoni, and adds complexities to creating the image. Due to these complexities, the project recommends Ventoy to create a live USB drive from the image. If problems are encountered, the project has a forum available to help solve them.

This article doesn't explore every CAE-related project included in the release; readers are encouraged to try the distribution themselves. CAELinux, while somewhat flawed, is a pretty interesting Linux distribution that provides a great example of the wide variety of engineering-related open-source projects out there.