AutoCAD’s model space and paper space provide a rich graphical interface for creating, displaying, and editing your models. This section describes how to manipulate these graphical interfaces. By default, AutoCAD creates one model space, and two paper space layouts when a drawing is created.
A viewport is a particular view of the drawing file, either in model space (TILEMODE=1) or paper space (TILEMODE=0). In model and paper space, viewports have different properties and are represented by objects of different types.
The current model space viewport configuration is contained in the AcDbViewportTable symbol table. The viewports in this configuration are represented by AcDbViewportTableRecord objects. Saved viewport configurations are contained in the AcDbViewTable symbol table and their views are represented by AcDbViewTableRecord objects. The model space viewports are always rectangular.
In a paper space layout, viewports are represented by AcDbViewport objects. These viewports can be complex clipped, that is they can be set to any arbitrary shape. In paper space, unlike model space, viewports do not need to be tiled. AcDbLayout objects, accessed from the ACAD_LAYOUT named object dictionary, describe the viewport configuration for that layout.
Viewports contain grid display, lighting, visual style, background, and camera settings.