When working with 3D printers, you start with an object file. The object is a solid chunk of 3D geometry. To get that out to the printer, it needs to be “sliced” into layers. This is similar to a laser printer. There, you start with a PDF or PostScript that defines a circle here and a wavy line over there, but a stage of the printing process ultimately needs to convert those mathematic shapes to a grid of tiny dots.
It’s a bit more complex with a 3D printer. There are solid outer shells. There’s an airy interior grid. There are overhangs and closures that need special handling. All of these things (and more!) are options that you can twiddle.
Interesting enough, there’s a piece of Mac software called Pleasant3D that lets you visualize the layering. This lets you see how tweaking individual options will affect the 3D print without having to go through with the print. Because these are visualizations of slices of the 3D model, inside and out, there are some strong parallels with Magnetic Resonance Imaging. Couple that with the animated gif kick I’ve been on recently and you end up with this pseudo-MRI of the Octocat:
I made this by first loading the *.gcode file into Pleasant3D. I then took screenshots of each layer, being careful to not move the window. I next used a small script to apply the ImageMagick convert command to each screenshot: crop them to just the content of the Pleasant3D window and resize. Those then pass through gifsicle to build out the animated gif.