The command Distance_Along_Path computes the distance travelled by a vector from the start to point p. In the figure below, the green line is the path travelled from the start to point P.

The pipeline command below will calculate the distance travelled by the MID_PSIS TARGET along its path.

Distance_Along_Path
/SIGNAL_TYPES=TARGET
/SIGNAL_FOLDER=ORIGINAL
/SIGNAL_NAMES=MID_PSIS
/RESULT_FOLDERS=PROCESSED
/RESULT_NAME=PSIS_DISTANCE
! /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=
! /EVENT_SEQUENCE=
! /EXCLUDE_EVENTS=
;

Visual3D also contains commands for the Distance Perpendicular to Path and Distance Parallel to Path. Or return to the Signal Commands overview.