learn path or teach motion , any ideas

has anyone implemented a learn or teach mode for EMC ?

looking at manualy tracing a path or scanning an object , then have a positional list of points or reference have this refered back to gcode
for emc to then re-trace the path . i'm hoping that logging the encoder positions along a path would suffice , along with a control reference point
may get somewhere close .

but has anyone a better soloution or idea

thanks John