Freesteel

Slice is a command line utility for cutting a 3D triangulated models saved in the STL file format with a plane in Z to produce a 2D shape. Output formats include plain text, HPGL, XML, or SVG (pictured).

Slice is free to use and distribute in its binary form. Download the Windows Installer here (size: 9Mb).

Slice is one of the fundamental algorithms used in Rapid Prototyping, although it can have other applications, such as generating contour lines on surfaces or creating silhouettes (available in version 2).

Examples. Create your own STL file, or download an example.

To create 11 slices from Z=10 to Z=20 every 1mm and output to a file, type:
slice -z 10,20,1 example.stl -o output.svg

If you do not know the Z range of your model, the following command prints it out:
slice -v example.stl

Question Why has my Z value been moved slightly? You probably asked for a slice that coincides exactly with a horizontal plane or was too close to a nearly horizontal plane. These cases can be ambiguous, so the algorithm moves the position slightly before slicing it. Most geometric algorithms perform this kind of fudging in the background to make them work, but don’t usually show what’s happened, so you never find out.

Question Why isn’t this algorithm open source? There is too little interest in this at the moment. We would like there to be more. If you are working with GPL-licensed software that needs to use slice, you can run it using a command-line call in a process known as aggregation. If this helps you produce something interesting, please get in touch.