// but if periodic, then the navigationCenter may have to be moved back a
// notch
Point3f pt = new Point3f(navigationCenter);
viewer.toUnitCell(navigationCenter, null);
// presuming here that pointT is still a molecular point??
if (pt.distance(navigationCenter) > 0.01) {
matrixTransform.transform(navigationCenter, pt);
float dz = navigationShiftXY.z - pt.z;
// the new navigation center determines the navigationZOffset
modelCenterOffset += dz;
calcCameraFactors();