There are some cat toys at home, which are deeply loved by the local "fur babies". These toys are simple hollow spheres with hollow grooves on the surface. They are small and lightweight, especially suitable for kittens to kick around. I stared at this object for several minutes, carefully contemplating its geometric structure, and suddenly had an inspiration: Isn't this a perfect entry-level teaching case? By using simple geometric shapes and Boolean operations, we can easily guide beginners into the world of 3D CAD modeling.

The main image shows the original model of the object

The detailed steps of model building have been fully documented on my blog, and the link is as follows:http://netninja.com/2012/03/24/from-atoms-to-bits-to-atoms-a-cat-toys-journey/

The final fully parameterized OpenSCAD file is attached to this document.