Inside-Out Linkage
The following 3D linkage effectively turns the edge skeleton
of a truncated tetrahedron "inside out".
Turning a polyhedron inside out is similar to reflecting it through a plane,
except that the inside/outside orientation of the faces is also inverted.
The animated GIF is 10 megabytes, so it may take a while to load in full;
then it should animate fairly quickly.
The animation was raytraced with POV-ray
by Erik Demaine.
Martin Demaine