Why would you want to do this, if there's a perfectly good VTK-format model exported by Slicer already? Well, VTK is an industry standard that is good for many open source software packages, but most commercial packages don't deal well with the format. So, STL ("stereolithography") files are a happy medium. STL format has its own issues, but is nearly universally read by computer modeling programs.
In order to get a start on exporting STL's from Slicer, let's return to where we picked up from the last tutorial. Load all of your files (you saved the model and label map after the last tutorial, right?). This should give you the brain in the middle of the 3D viewer. For some unknown reason, say you want to export this brain as an STL for post-processing in another program. Luckily, it's a relatively easy thing to do!
First, switch to the "Models" module, by selecting under the "Modules" drop-down menu.
Then, click on the "Save" tab, to expand this option. Hit the "Save Model" button.A dialog box comes up, and you can choose an alternative from the default (VTK) under the "Files of Type" option. In this case, select "STL."
Choose the name and location for your file, hit save, and you're done!
