A VisGroup is a group that contains different objects that can be toggled between hidden and visible. These are useful for keeping your map organized and reducing visual clutter.

The VisGroups toolbar is located to the right of the four viewport windows. There are two tabs available for organizing your VisGroups: User and Auto. The User tab contains all the VisGroups that you create, while the Auto tab organizes all the individual items into lists so you can activate and deactivate them whenever you'd like.

With the example map loaded, turn of all VisGroups except for World Geometry to see what the world is made of.

You should see something similar to the preceding screenshot. Note that on the left-hand side, you can see the all the entities and special brushes. However, on the right-hand side, you only see the floor, walls, and ceiling. If your map is getting cluttered, try turning off some specific VisGroups to make your life easier. VisGroups will affect the 2D view as well as the 3D view.

If you would like to create your own VisGroup, select a group of objects and go to View | Move Selection to Visgroup. Alternatively, you can hit the Move to VisGroup button on the toolbar at the top of the screen. It looks like a cube with red dotted lines (outlined in a red box in the following screenshot):