Minor correction: Fusion, FreeCAD and similar are parametric. It means you can alter the parameters of the created object after the fact and it rebuilds accordingly, as opposed to "destructive editing" like you have in something like Rhino 3D.
In an other article I published I wrote: When we think of 3D modeling, we imagine a user interface where we can, with a single click, stretch a 2D rectangle and then extrude it; again with a click, we can select an edge and apply a fillet.
This is typically what we do with Fusion 360 or open-source software like FreeCAD. In fact, this is parametric modeling. The graphical interface, where you can rotate or zoom in on your 3D model, is just that — an interface, as its name suggests.
However, behind the scenes, the software is managing parametric modeling. To illustrate this, it is entirely possible in these programs to edit a shape and assign a new value to a given edge or cylinder. This is possible because it’s parametric modeling.
sylvainFR•2mo ago
The entire model generation process is powered by build123d, a Python CAD library built on top of OpenCascade. Every 3D preview and thumbnail is automatically rendered using Blender through a fully automated server-side pipeline.
Beyond simply offering a free on-demand service, iteration3d also serves as a practical showcase of what’s possible with build123d. This growing CAD library is quickly gaining attention in the Python and parametric modeling communities.
If you're curious about how everything works, I’ve written a detailed tutorial explaining the model-generation process using build123d (see link)
The project has also been referenced by OpenCascade, the geometric kernel behind build123d and widely used in software like FreeCAD.