/// <summary>
/// Extract a point that represents the scale associated with each row
/// </summary>
/// <returns></returns>
public Vector3D ExtractScale()
{
Matrix3D mTemp = new Matrix3D(this);
// undo translation
mTemp._elements[12] = 0;
mTemp._elements[13] = 0;
mTemp._elements[14] = 0;
// undo rotation
Quaternion quat = Quaternion.FromTransform(this);
Quaternion quatInverse = quat.GetInverse();
mTemp.Rotate(quatInverse);
// all that's left is scale?
return(Vector3D.FromXYZ(mTemp._elements[0], mTemp._elements[5], mTemp._elements[10]));
}
/// <summary>
/// Extract a quaternion that represents the matrix' current rotation
/// </summary>
/// <returns></returns>
public Quaternion ExtractRotation()
{
return(Quaternion.FromTransform(this));
}
// ================================================================================
/// <summary>
/// Extract the matrix' current rotation as an axis and a rotation
/// </summary>
/// <param name="axis"></param>
/// <param name="radians"></param>
public void ExtractAxisAngle(out Vector3D axis, out float radians)
{
Quaternion quat = Quaternion.FromTransform(this);
quat.GetAxisAngle(out axis, out radians);
}
