The Hide Unmasked button hides all polygons with a mask value of less than 50%, making them invisible. This provides a means of creating holes in the surface of the object.
Once hidden, polygons can be un-hidden by pressing the ShowPt button.
The Show Points button un-hides all polygons with a mask value of less than 50%, making them visible again if they have been hidden with the Hide Unmasked button.
The Grow button increases the visible polygons by unhiding the border polygons, one loop at a time. This function doesn’t add polygons, it just reveals previously hidden polygons.
The Shrink button decreases the visible polygons by hiding the border polygons one loop at a time. This function doesn’t remove polygons, it simply hides visible polygons.
When the Grow All button is pressed the partially visible mesh will become completely visible based on the geometry shell. This may mean the whole SubTool is shown, or only a part if it is composed of separate pieces.
The Outer Ring button will hide everything except the outer ring of the visible polygons.