The Metric_Golf_Swing_Plane command computes the best fit plane to the trajectory of a TARGET or LANDMARK signal, usually defined within a specific event sequence (e.g., the golf swing phase).

The underlying calculation uses Visual3D's Best Fit Plane method- a least squares fitting procedure that determines a plane which best fits the path of a point from a START event to an END event. This plane is defined by four coefficients (a, b, c, and d) in the equation.

ax+by+cz+d = 0, where (a, b, c) is the normal vector to the plane.

In a standard Best Fit Plane calculation, the normal vector can point in either of two opposite directions. In the case of this command, the calculation includes an additional check to ensure that the plane's normal always points away from the pelvis- providing a consistent and meaningful orientation for golf swing analysis.

The golf swing plane is defined as the best fit plane to a time series of points of a TARGET or LANDMARK, usually defined within an event sequence.

The purpose of the event sequence is to allow the computation of different planes through the swing. For example, a plane during takeaway.

Metric_Golf_Swing_Plane
/SIGNAL_TYPES=TARGET 
SIGNAL_NAMES=CLUB 
/SIGNAL_FOLDER=ORIGINAL
/RESULT_NAME=STANCE_CLUB
/RESULT_FOLDER=GOLF
/EVENT_SEQUENCE=TAKEAWAY+BACK
! /EXCLUDE_EVENTS=
;

or a plane at the beginning of the backswing.

Metric_Golf_Swing_Plane
/SIGNAL_TYPES=TARGET
/SIGNAL_NAMES=CLUB
! /SIGNAL_FOLDER=ORIGINAL
/RESULT_NAME=SWING_CLUB
/RESULT_FOLDER=GOLF
/EVENT_SEQUENCE=TOP+DOWN
! /EXCLUDE_EVENTS=
;

The dialog for this command is:

To display the two swing planes use the command Highlight_Golf_Features:

Highlight_Golf_Features
! /CALIBRATION_FILE=
! /X_FACTOR=RPV::X+RTA::X
CLUB_PATH=TARGET::ORIGINAL::CLUB
! /BALL_PATH=TARGET::ORIGINAL::BALL
/STANCE_PLANE=METRIC::GOLF::STANCE_CLUB
/SWING_PLANE=METRIC::GOLF::SWING_CLUB
/HIGHLIGHT_X_FACTOR=TRUE
/HIGHLIGHT_CLUB_PATH=TRUE
/HIGHLIGHT_BALL_PATH=TRUE
/HIGHLIGHT_STANCE_PLANE=TRUE
/HIGHLIGHT_SWING_PLANE=TRUE
;

Given the dataset, it has been difficult to generalize a good view of the swing planes. One image is below.