-- <b>Gravity Center of Select Object</b> button allows to choose Point, Edge, Face or Volume in drop-down menu.
- As soon as corresponding object is selected in the viewer, its gravity center will be used as center of the rotation point.
+- <b>Gravity Center of Selected Object</b> button allows using the gravity center of the object selected in the viewer as the center of the rotation point.
+When you click this button, you should first choose the type of selectable object: Point, Edge, Face or Solid and only then proceed with selection in the viewer.