View Tab >
F
Fits all visible or selected objects in the active view. If you select one or more objects before clicking Fit, the software fits only the selected objects in the view. However, if you do not select any objects, then all visible objects in the clipping volume display in the view. Clicking Fit does not cancel any previous commands. When the fit completes, Smart 3Dx returns to the previous command.
Fit (F)
Displays all of your selected objects in the active view.
Fit All (SHIFT + Fit)
Displays the visible objects in the active view.
Fit Visible in All Views (A + Fit)
Displays the selected objects in all of the views.
Fit Visible (A + SHIFT + Fit)
Displays the visible objects in all of the views.