Hiding and Showing Model Parts

From ZBrush Info

Before proceeding, let’s quickly go over the selection features. The core of these features is the Ctrl+Shift key combination. All mesh visibility options involve those two keys.

When a mesh is completely visible, Ctrl+Shift+Clicking on any group will hide everything except that group.

When a mesh is partly visible, Ctrl+Shift+Clicking on a group will hide that group.

When a mesh is partly visible, Ctrl+Shift+Clicking on the blank canvas will restore full visibility. At any time, holding Ctrl+Shift while dragging across the model will activate a green selection box. Any polygons within that box when the mouse button is released will remain visible. All other polygons will be hidden.

If the keyboard is released before the mouse button, the box turns red. Any polygons within the box will be hidden while the rest of the mesh remains visible.

Dragging a small box (of either color) on any empty part of the canvas will invert the visibility.

The drag-rectangle selections use a “smart” system. If the drag rectangle encloses an entire polygon, then the system will select by polygons, only. In other words, a polygon must be fully enclosed by the box to be selected. If no polygon is completely enclosed, then the system will select by points instead. You can also force point selection by activating the Pt Sel switch on the right shelf.