Throughout this book, you will see a distinction between “DWG objects” and “features.” For example, you may see sentences like “import SDF features to DWG objects” or “create new features from existing DWG objects.” It is very important to understand this distinction. AutoCAD Map 3D works with both DWG objects and with GIS features. GIS features look like DWG objects, in the sense that they are displayed on the screen as lines, polygons, and points, but they are completely different in the way that they are stored, accessed, and managed. Here are some of the most important differences.
The reason it is important to understand these differences is that there are commands in AutoCAD Map 3D that work on features but not on DWG objects (and vice-versa). For example, most of the skills in this book apply only to features, because the assumption is that you are already familiar with DWG objects. However, we have included some skills that deal with DWG objects, partly for the sake of completeness, and partly to provide you with essential AutoCAD Map 3D skills if you are a new user or if you are making the transition from AutoCAD.