Friday, June 7, 2019

Digitizing Specifications

To use the options provided by the MAPDIGITIZE command, you must configure the digitizer and register the map.

Attaching Data

You can link data to objects as you digitize. Although you can store data in AutoCAD Map 3D as block attributes, you can perform more sophisticated analysis of the data if you use one of the following methods:
  • Data linked to an object is stored as object data in the drawing.
  • Data linked to an object is stored in an external database.

Label Point

label point is the point used to insert text to describe the digitized object. You can specify a label point for each object as you digitize.

Layer

Plan the layers you will use in your drawing. A layer is a logical grouping of data, which simplifies organizing and viewing data. For more information, look up "layers, creating" in the help index.
Each object that represents a different type of map data should go on a separate layer. For example, a polyline representing a coastline could go on a layer named COASTLINE, interstate highways on a layer named INTERSTATE, land boundaries on a layer named LOTS.
If you have not established a scheme for layer names, you can create one using the numeric feature-classification code found in some digital source data. For example, major roads might be on a layer named "170-201". A better naming convention combines names that suggest their function and a structure that allows selection with wild cards and groups of layer names. For example, you might decide that all topographic objects should go on layers beginning with the letters TP. So you might put rivers on a layer named TP_RIVERS, and contours on a layer named TP_CONTOURS. To freeze, thaw, lock, or unlock all layers with topographic data, you use the expression TP*. For more information on wild-card characters, look up "wild-card characters" in the help index.

Block Name or Linetype

To represent nodes using blocks available in the current drawing, select a block name or ACAD_POINT for the block name.
Choosing ACAD_POINT places a point object at each node position. For information about changing the appearance of this point object, look up DDPTYPE in the help index.
Wherever possible, use the linetypes supplied with AutoCAD Map 3D to indicate different types of boundaries, road types, and waterways. Using standard linetypes ensures consistency across maps and helps you keep track of what you have digitized. Associate each linetype with a different layer.

Object Snap

Use object snap to tie nodes or segments to linear objects that are already in place. For example, always use object snap to position junctions of pipes, roads, or railways.

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