A sheet layer viewport or design layer viewport (Design Series required) shows a specific portion of one or more design layers. The original location of the viewport layers can be either within this file or another file. The view parameters in the viewport can be different from those of the original layers. For example, the scale, layer and class visibility, or render mode might be changed to create a certain effect. A sheet layer viewport does not always automatically change when the underlying drawing does. To see the drawing changes that were made after a sheet layer viewport was created, update the viewport. One or more viewports can be placed on a sheet layer or design layer, to show various parts of the drawing project in different ways.