Showcase supports several keyboard shortcuts for navigating around a scene; in other words, rotating (tumbling), moving up down, left or right, or in and out (zoom). This enables you to use the methods you are accustomed to in other Autodesk products such as Revit, Inventor and AutoCAD. See the viewport shortcuts in General keyboard shortcuts.
Present a scene in presentation mode
In presentation (view-only) mode, you can orbit or walk around a scene, but not change it in any way. Most interface elements and windows are temporarily hidden. (They appear again when you return to edit mode, without any loss of data.)
You can tell you are in presentation mode when the message at the bottom says “Orbit”.
(If the message says “Select,” you are in edit mode and can select and change objects.)
For more information on presenting your scene, see Present the scene.