Bond contacts with the gap interval specified. If only one value is specified this is the
upper bound of the interval. If two values are specified they correspond to the lower and
upper bounds of the interval, respectively. By default the interval is .
sj_setforce
Set the smooth-joint normal force from the current contact force.
Unbond contacts with the gap interval specified. If only one value is specified this is the
upper bound of the interval. If two values are specified they correspond to the lower and
upper bounds of the interval, respectively. By default the interval is .