TExternallyCalculatedImposedMotionStructValue

TExternallyCalculatedImposedMotionStructValue is the data structure used to represent the calculated value for a vessel primary motion external function, or a constraint imposed motion external function. The value is passed in the lpStructValue field of TExtFnInfo.

The fields in this structure define, in 6 degrees of freedom, the position, velocity and acceleration of a child-frame relative to a parent-frame.

For vessel primary motion, we define the parent-frame to be the global axes, and the child-frame to be the vessel primary axes.
For constraint imposed motion, we define the parent-frame to be the constraint in-frame, and the child-frame to be the constraint out-frame.

typedef struct {

int Size;

TVector Position;

TMatrix Orientation;

TVector Velocity;

TVector AngularVelocity;

TVector Acceleration;

TVector AngularAcceleration;

} TExternallyCalculatedImposedMotionStructValue;

Members

Size

Specifies the size, in bytes, of this data structure. This member is set by OrcaFlex before it calls the external function.

This member must not be altered.

Position

The position of the child-frame, relative to and with respect to the parent-frame.

Orientation

A 3 by 3 matrix containing the orientation of the child-frame, relative to the parent-frame. The rows of this matrix are unit vectors in the child-frame axes directions, expressed as vector components with respect to the axes of the parent-frame.

Velocity

The velocity of the child-frame, relative to and with respect to the parent-frame.

AngularVelocity

The angular velocity of the child-frame, relative to the parent-frame, but reported with respect to the axes of the child-frame.

Acceleration

The acceleration of the child-frame, relative to and with respect to the parent-frame.

AngularAcceleration

The angular acceleration of the child-frame, relative to the parent-frame, but reported with respect to the axes of the child-frame.