/// <summary>
/// From a Vector director, Get the quaternion representing this vector
/// the up vector can be Vector3.up if you have no reference.
/// </summary>
/// <param name="vectorDirector"></param>
/// <param name="upNormalized">default is Vector3.up</param>
/// <returns>Quaternion representing the rotation of p2 - p1</returns>
public static Quaternion QuaternionFromVectorDirector(Vector3 vectorDirector, Vector3 upNormalized)
{
Matrix4x4 rotationMatrix = ExtMatrix.LookAt(vectorDirector, vectorDirector * 2, upNormalized);
Quaternion rotation = rotationMatrix.ExtractRotation();
return(rotation);
}
/// <summary>
/// From a Line, Get the quaternion representing the Vector p2 - p1
/// the up vector can be Vector3.up if you have no reference.
/// </summary>
/// <param name="p1">point 1</param>
/// <param name="p2">point 2</param>
/// <param name="upNormalized">default is Vector3.up</param>
/// <returns>Quaternion representing the rotation of p2 - p1</returns>
public static Quaternion QuaternionFromLine(Vector3 p1, Vector3 p2, Vector3 upNormalized)
{
Matrix4x4 rotationMatrix = ExtMatrix.LookAt(p1, p2, upNormalized);
Quaternion rotation = rotationMatrix.ExtractRotation();
return(rotation);
}
/// <summary>
/// usage to rotate around a transform using this:
/// Matrix4x4 currentTRSTransform = ExtMatrix.GetMatrixTRS(_currentOrbitter);
/// Matrix4x4 newMatrixTrs = ExtMatrix.RotateAround(currentTRSTransform, _pivotTransform.position, _offsetRotate, Time.deltaTime * _speed);
/// _currentOrbitter.FromMatrix(newMatrixTrs);
/// </summary>
/// <param name="customTransform"></param>
/// <param name="center"></param>
/// <param name="axis"></param>
/// <param name="angle"></param>
/// <returns></returns>
public static Matrix4x4 RotateAround(Matrix4x4 customTransform, Vector3 center, Vector3 axis, float angle)
{
Vector3 pos = customTransform.ExtractPosition();
Quaternion rot = Quaternion.AngleAxis(angle, axis); // get the desired rotation
Vector3 dir = pos - center; // find current direction relative to center
dir = rot * dir; // rotate the direction
Vector3 finalPosition = center + dir;
// rotate object to keep looking at the center:
Quaternion myRot = customTransform.ExtractRotation();
Quaternion finalRotation = myRot * Quaternion.Inverse(myRot) * rot * myRot;
Vector3 localScale = customTransform.ExtractScale();
Matrix4x4 newTrsMatrix = ExtMatrix.GetMatrixTRS(finalPosition, finalRotation, localScale);
return(newTrsMatrix);
}
