TVesselInstantaneousCalculationData

The TVesselInstantaneousCalculationData contains information about the instantaneous state of a vessel. This information is available for applied load external functions for vessels.

typedef struct {

int Size;

TVector Position;

TMatrix Orientation;

TVector Velocity;

TVector AngularVelocity;

TVector LFPosition;

TMatrix LFOrientation;

TVector LFVelocity;

TVector LFAngularVelocity;

TVector WFPosition;

TMatrix WFOrientation;

TVector WFVelocity;

TVector WFAngularVelocity;

} TVesselInstantaneousCalculationData;

Members

Size

Specifies the size, in bytes, of this data structure.

Position, Orientation, Velocity, AngularVelocity

These members give the position and velocity of the vessel origin due to all vessel motion (including superimposed motion if any is specified), as follows:

Position contains the global axes X,Y,Z coordinates of the position of the vessel origin relative to the global origin.
Orientation is a matrix containing the orientation of the vessel, relative to global axes. The matrix is in row-major order, so the first 3 elements are the first row, the next 3 the second row and the last 3 the third row. These rows contain the global axes components of the unit vectors in the vessel local x-, y- and z-axes directions: the first 3 elements of the matrix (first row) are the global axes components of the vessel local x-direction, the next 3 elements (second row) are the global axes components of the vessel local y-direction, and the last 3 (third row) are the global axes components of the vessel local z-direction.
Velocity contains the X,Y,Z components, in the global axes directions, of the velocity of the vessel origin relative to global.
AngularVelocity contains the x,y,z components, in the vessel axes directions, of the angular velocity of the vessel relative to global.

Note:

This AngularVelocity vector is given in vessel axes components, not global axes components.

LFPosition, LFOrientation, LFVelocity, LFAngularVelocity

These are the same as Position, Orientation, Velocity and AngularVelocity, described above, except they only include the low frequency part of the primary motion. They are expressed as components in the same way as the total primary position and motion results, described above.

WFPosition, WFOrientation, WFVelocity, WFAngularVelocity

These are the same as Position, Orientation, Velocity and AngularVelocity, except they only include the wave frequency part of the primary motion, and they are relative to the low frequency position and orientation of the vessel. They therefore report the total primary motion position and velocity of the vessel, relative to its position and velocity after only the low frequency part of the primary motion has been applied. In particular:

WFPosition is the offset of the vessel origin due to the wave frequency part of the primary motion, relative to its position due to the low frequency primary motion. This offset is expressed as components in the directions of the vessel axes after only the low frequency part of the motion has been applied.
WFOrientation is the orientation matrix for the wave frequency part of the primary motion. It is therefore the orientation matrix of the vessel axes directions after all primary motion has been applied, relative to their directions after only the low frequency motion has been applied. The rows of WFOrientation contain the unit vectors in the vessel local x-, y- and z-axes directions after all primary motion has been applied, expressed as components in the directions of the vessel axes after only the low frequency part of the motion has been applied.
WFVelocity is the wave frequency part of the translational velocity of the vessel origin, expressed as components in the directions of the vessel axes after only the low frequency part of the primary motion has been applied.
WFAngularVelocity is the wave frequency part of the angular velocity of the vessel, expressed as components in the directions of the vessel axes after all the primary motion has been applied.