Inverts this quaternion in place.
SIQuaternion.InvertInPlace();
dim q1 ' Create Quaternion. set q1 = XSIMath.CreateQuaternion(1.0, 1.0, 2.0, 3.0) q1.InvertInPlace
SIQuaternion.Invert SIVector3 SIMatrix3 SIMatrix4 SIRotation SITransformation SIQuaternion