PartCAD

PartCAD is the standard for documenting manufacturable physical products. It comes with a set of tools to maintain product information and to facilitate efficient and effective workflows at all product lifecycle phases.

PartCAD is more than just a traditional CAD tool for drawing. In fact, it's not for drawing at all. The letters "CAD" in PartCAD stand for "computer-aided design" in a more generic sense, where "design" stands for the process of getting from an idea to a clear and deterministic specification of a manufacturable physical product using a computer (including the use of AI models). While PartCAD started as the first package manager for hardware, it is now the next-generation CAD that can turn a single visionary individual into a one person corporation, or make one future Product Manager as productive (and much faster!) as 10 corporate engineering departments of the past.

PartCAD is constantly evolving, with new features and integrations being added all the time. Contact us to discuss how PartCAD can revolutionize your product development process.

PartCAD VSCode Extension

This extension helps create PartCAD packages and explore packages that are already published. To learn more about PartCAD, see the documentation or the project repo. Also, make sure to visit our website and browse the repository of published 3D models.

Digital Thread

Selecting a part, assembly, scene, sketch or interface opens it in the Digital Thread tab. PartCAD tessellates the shape in a sandboxed runtime and sends the result to this extension as compressed glTF over a socket on 127.0.0.1:9137, so the viewer needs no CAD library of its own. The Python side of that connection is the partcad_ide_client package, which ships inside partcad itself.

Anything that can reach that port displays into the same viewer, including a pc ide view run in a plain terminal. Set PARTCAD_IDE_PORT to move both ends off the default port.

The panel is a strip of tabs over the one object, not just a canvas: groups, Design (the object itself), Analysis (analysing it), Manufacturing (making it) and Validation (whether it does what it is supposed to), each with tabs of its own, then Operations, which is always disabled for now. An object that declares requirements: has a Requirements tab in front of all of them. Every group shows all of its tabs, disabling what does not apply, and Analysis, Manufacturing and Validation are disabled themselves when none of theirs does - hovering over a disabled group says why; each opens on the tab last opened in it while that one applies, and on the first that does otherwise.

Only the 3D view comes over the viewer protocol. The others are questions about <package>:<name> that this extension puts to the PartCAD daemon, fetched the first time a tab is looked at and cached until the next object is shown — so an object belonging to no package gets the 3D view alone. In a window without WebGL — a virtual machine, a remote desktop, a GPU the editor could not use — the 3D view and the FEA and CFD models are drawn with WebGPU where the window has it, and without the graphics card otherwise: flat-shaded and slower, with a big model drawn as boxes while it is being turned. It says so in a corner, and hovering there says how to have the graphics card back.

3Dconnexion SpaceMouse

The 3D view, and the model of an FEA or CFD result, can be navigated with a 3Dconnexion SpaceMouse: the cap moves the model the way it is pushed and twisted, and the Fit button (the right-hand one on a two-button device) frames it again. On Windows and macOS the viewer reads the device on its own — move the cap once with the viewer open for the editor to notice it. On Linux it reads it from spacenavd, which has to be installed and running (sudo apt install spacenavd, for example). Only the viewer in the focused window moves, and only the tab on screen. partcad.spaceMouse.sensitivity sets the speed, partcad.spaceMouse.invert reverses individual axes, and partcad.spaceMouse.enabled turns it off.

On Linux, spacenavd is read by the part of the extension that runs where the workspace is. In a remote window — a container, an SSH host — that is not the machine the SpaceMouse is plugged into, so spacenavd's socket has to be brought there; the PartCAD output says so when a remote window finds none. PartCAD's own development container binds the host's (restart the container after restarting spacenavd). Over Remote-SSH, forward it in ~/.ssh/config, where 1000 is your user id on the remote machine (id -u there):

Host my-workstation
    RemoteForward /run/user/1000/spnav.sock /var/run/spnav.sock

StreamLocalBindUnlink yes in the remote machine's sshd_config lets a reconnection replace the socket a dropped one left behind.

The PartCAD terminal

What PartCAD is busy with -- its log and the progress of a long operation -- appears in the PartCAD terminal. It opens the first time there is something to show, to the right of a shell named Shell: a terminal running your default shell, with the PartCAD command line tools on its PATH, for starting a coding agent side by side with what PartCAD is doing.

Close it whenever you like. It stays closed until you run PartCAD: Show Terminal or pick PartCAD from the terminal panel's + menu, and then it opens with everything it missed. Set partcad.reopenTerminal to true to have new output reopen it instead, and partcad.popupTerminal to bring it to the front on every new line. If PartCAD stops working in the window -- no PartCAD service, or one that will not start or keeps stopping -- it opens on its own and says why, with a popup if it was closed.

The command line in the integrated terminal

While the extension is active, terminals opened in the window get the PartCAD command line tools on their PATH, so pc and partcad work without installing anything separately or editing a shell profile. VS Code marks such a terminal and will show you which extension changed the environment. Terminals already open when the extension activates keep the environment they started with; reopen one to pick the tools up. Set partcad.addToolsToTerminalPath to false to keep a PartCAD of your own on the PATH instead.

Creating PartCAD packages

After this extension is installed, the PartCAD workbench becomes available.

Usually, the first step suggested by the workbench is to initialize the current workspace as a new PartCAD package. After that new parts and assemblies can be added using the corresponding buttons in the PartCAD explorer view.

Creating parts

If you have a CAD file created in some other tool then click the Add a CAD file to the current package button in the PartCAD Explorer's toolbar (hover the mouse over the middle left view to see toolbar icons on the top of the view) and select the file (STEP, STL, 3MF etc) from the current workspace.

If you want to add a script file (CadQuery, build123d, OpenSCAD etc) that you can edit in VS Code, then click the Add a CAD script to the current package button in the PartCAD Explorer's toolbar. If you select a file that does not exist then you will be prompted for the template to use.

When you edit scripts that are registered in the current PartCAD package, saving the file makes it displayed in the Digital Thread view.

Creating assemblies

This is what PartCAD (or, at least, its VS Code Extension) is actually for.

Click Add an assembly file to the current package and select a file with the ".assy" extension. ASSY (Assembly YAML) follows YAML syntax. The list of parts has to be added as children under the links node.

Select the desired part or assembly in PartCAD Explorer. After that navigate to the next line under the links node and type "- pa" (which is what you do when you want to add a child item with the name "part") and let VS Code use the first suggested code completion suggestion. This will add the selected part or assembly to the currently edited assembly.

When you edit ASSY files that are registered in the current PartCAD package, saving the file makes it displayed in the Digital Thread view.

Checking assemblies while you edit

An ASSY file is a Jinja2 template that renders to YAML, and the result has to match the ASSY schema. The extension checks all three of those while the file is open -- template errors, YAML errors and schema errors, such as a mistyped key or a location that is not an OCCT location -- and reports them in the Problems view at the line they came from. A file that uses {% for %} loops or {{ parameters }} is checked as it renders, with the default values of the parameters its declaration in partcad.yaml gives it: a finding inside a loop is reported once, at the loop's body, and one about a computed value at the {{ }} that computed it. A file no package declares yet is checked without rendering, and anything that depends on a template value is left out rather than guessed at. An assembly or a part marked manufacturable: true is also held to what something that is to be made needs: items connected rather than placed, and parts that say how they are made or bought.

The PartCAD > Lint settings say how:

• partcad.lint.enabled turns the check off.
• partcad.lint.includePaths adds directories that templates may {% include %} from, relative to the workspace folder -- for files a package above yours provides through includePaths, when that package is not in a directory above the file.
• partcad.lint.extraParams renders files with other parameter values than their defaults, written as pc --extra-param takes them: desk.length=60 (or //pub/furniture:desk.length=60).

ASSY files and partcad.yaml are languages of their own in the editor, "PartCAD ASSY" and "PartCAD Package Configuration": highlighted as YAML, with the template's {% %}, {{ }} and {# #} tags highlighted on top. That also keeps YAML extensions from checking them as plain YAML, which reported template tags such as {% for %} as errors.

With Code Spell Checker installed, the words these files are written in -- assy, cadquery, connectPorts, every other key and value the ASSY and package schemas spell, and Jinja2's endfor -- are not flagged as typos in them. Everything else, such as a desc:, is still checked.

Opening an object in another application

Right-click an object in the PartCAD Explorer and pick Open in > ... to open the file it is defined by in the application that made it. It is the object's own source file that is opened, so this is the way to reach it in a tool that draws, next to what the extension does with it.

• FreeCAD, for a part or an assembly.
• Blender, for a part or an assembly. Blender reads meshes and nothing else, so an object that is not already one (a STEP file, a CadQuery script) is converted to STL first and Blender is given that; an STL, an OBJ or a glTF is imported as it is. The converted copy lives under PartCAD's own directory for this workspace, never beside your file, and is reused until the object changes.
• Gazebo, for a scene that is a Gazebo world -- one of type sim-gazebo:world, which is also what pc export -S -t sim-gazebo:world writes out of any scene.
• MuJoCo, for a scene that is an MJCF model -- one of type sim-mujoco:mjcf, which is also what pc export -S -t sim-mujoco:mjcf writes out of any scene. MuJoCo reads MJCF and no other model format, and nothing converts a world into it on the way: MJCF is written by the MuJoCo plugin package, which the file handed to MuJoCo has no package around it to reach.
• KiCad, for a part of type kicad. What is opened is the board (.kicad_pro) beside the STEP the part is, because that is the file KiCad has anything to say about.

This runs on your machine and never goes anywhere near the PartCAD daemon: the extension runs pc ide open, which looks for the application installed here and starts it. If there is none, and partcad.open.useDocker is on (the default), PartCAD runs it in a Docker container instead -- one container per application, created from its image (or partcad.open.dockerImage) the first time and reused afterwards, with the file mounted at the path it has here, or, with useDockerRemote on, sent to the container and back. Its windows come out on your X display. On Linux that is the display you are already using; on macOS and Windows it needs an X server (XQuartz, VcXsrv) that PartCAD cannot install for you, so it tells you which one to install and what to allow rather than starting a container whose windows go nowhere. pc system prune removes these containers like every other one PartCAD starts. Turn partcad.open.useDocker off to use installed applications only. Either way, a machine that has neither the application nor Docker is told so rather than left with a menu entry that quietly does nothing.

While the application is open, VS Code waits for it: a banner fills the editor saying what is being edited and where, and every PartCAD command is paused, so that nothing is built from a version that is about to be replaced. Make your changes, save them and close the application; what you saved is brought back into the object's own file -- converted back into its format, when it had to be converted to be opened (a STEP part opened in Blender comes back as STEP). A part generated by a script cannot be written back into, so its edit is kept where it was made and the message says where. Stop waiting on the banner, or Cancel on the progress notification, gives you the editor back and leaves the application open, but what you save in it after that is not brought back.

Inspecting published PartCAD packages

To see a good example of a package with parts, it is recommended to browse pub -> robotics -> parts -> gobilda.

To see a basic example of a package with assemblies, it is recommended to browse pub -> furniture -> workspace -> basic. Please, note, that there are customizable parameters that can be tweaked in the PartCAD Inspector view (the bottom left view).

To see an example of a package with more complex assemblies, it is recommended to browse pub -> robotics -> multimodal -> openvmp -> robots -> don1. Please, note, that it takes A LOT OF resources to render the full robot assembly. It's easier to test some parts of the robot like link-lower-arm or link-base.

Implementation notes

Where PartCAD itself comes from

This extension is a client. It talks to a partcad-json-rpc executable, and it finds one in this order: the partcad.servicePath setting, an existing standalone installation, a bundle it downloaded before, ~/.local/bin, and finally your PATH. That last one means pip install partcad in a Python environment of your own is enough — the extension picks it up and downloads nothing. If it finds none of them, it offers to download a standalone bundle, which needs no Python at all.

Nor any conda: PartCAD builds every shape in a conda sandbox, and the bundle carries the conda that builds it, so a machine with none still renders parts. A conda or mamba you have installed is used in preference to the bundled copy — see the standalone README.

pc upgrade run inside a bundle this extension downloaded will refuse and tell you to update the extension instead: the extension owns that bundle, and upgrading it from underneath would leave a copy the extension does not know about.

More documentation

To learn more about PartCAD and for a more detailed tutorial, see the PartCAD documentation website.