image drawing a simple line from a to b.
the work points are still at a and b, but the line is longer/shorter.
double click on the line to access the extension values and modify them.
now the workpoints are still at a & b, but the line changes again.
I imaging the workpoints would need to be points, not nodes.
and the line would have to be bound to the with xdata or a persistant reactor of some sort.