Github, everyone’s favorite nerdery, added support for STL object files — essentially a system for uploading and rendering 3D models — in April. Now, however, they have enhanced their service with a system to find differences in later versions of these 3D files, essentially adding an undo button to 3D modeling.
The system, as demonstrated here, takes two or more STL files and overlays them, allowing you to see the differences and changes over time. The folks at GH write:
How does this work? We take both versions of the model and, using binary space partitioning, we calculate the added, deleted and unchanged parts. This is done using csgtool, a C library paired with a Ruby gem through FFI. These parts are cached and displayed by the 3D viewer we already have, although we color them differently and play with their transparency to help illustrate the changes.
You can see the review slider in action here, but basically it takes each version and then overlays the next using nice transitions. Kind of like code diffs – the processes of comparing two iterations of software – it gives you a lot more control over the design process and lets you see where someone messed up (or did something wrong). ‘incredible).
Unlike Thingiverse and YouMagine, however, Github is agnostic when it comes to printers and model types, so it’s a safe place for almost any printer user to play and work.