Here, d is the shortest distance between the source and destination axes,
rs and
rd are the radii of the source and destination cylinders.
Here, Xsrc and
Xdst are the undeformed location of the source and destination centers,
usrc and
udst are the corresponding displacements, and
es is the direction vector of the source axis.
Here, Xsrc and
Xdst are the undeformed location of the source and destination centers,
usrc and
udst are the corresponding displacements, and
es and
ed are the direction vectors of the source and destination axes.