Add min z height orientation search

src/slic3r/GUI/Jobs/RotoptimizeJob.hpp

@@ -27,9 +27,9 @@ class RotoptimizeJob : public PlaterJob
               "structures.\nNote that this method will try to find the best surface of the object "
               "for touching the print bed if no elevation is set.")},
            // Just a min area bounding box that is done for all methods anyway.
-           {L("Smallest bounding box (Z axis only)"),
-            nullptr,
-            L("Rotate the object only in Z axis to have the smallest bounding box.")}};
+           {L("Smallest Z height"),
+            sla::find_min_z_height_rotation,
+            L("Rotate the model to have least z height for faster print time.")}};
 
     size_t m_method_id = 0;
     float  m_accuracy  = 0.75;