PRODUCT FOCUS
AutoCAD Map 2014
Pay particular attention to the Default under Property Attributes. When you picked the entity on which to base the object class, Map assumes that the data of that object is the default. You may not want that, so I would leave the Default property blank. Otherwise when you classify new objects, each one will have the same data attached to it. Not a huge deal since you’ll have to add the new data either way, but at least if it’s blank, you’ll know that it hasn’t yet been edited to include the proper data. Once you’ve modified, included, and added all the properties you need, simply click “Save Definition.” You should now see your new definition appear below “Object Classes” (see Figure 2c).
Figure 3b: The results
Step 3: The Fun Part Now that you’ve created your new definition file and object classes, it’s time to put them to use. In this example, I’m using the City of Mandan’s city map, which is a basic CAD drawing. I want to create a system similar to Bismarck to the Mandan drawing. Once you open the drawing (if you exited out of AutoCAD, you will need to login again). Go to Map Explorer on the Task pane and right-click on “Object Classes.” Next click on “Attach Definition File” and choose the file you want. We next want to classify specific objects. In this example I want to start with the subdivisions. Luckily, they are all on a Subdivision layer, so I isolate it. I then right-click on the appropriate definition—in this case Subdivisions—and choose “Classify Objects.” (Note: all of these commands are available on the Create tab on the toolbar in the Drawing Object section.) A dialog pops up asking if you want to include and/or exclude certain objects (see Figure 3a).
These options can be quite handy, as was mentioned earlier in the discussion about excluding text or points and excluding objects that have been previously classed so you don’t accidentally override existing data. Once I check/uncheck what I need, I’m asked to select the objects I want to classify. In this example, I choose everything on the Subdivision layer. Figure 3b shows the data now attached to the subdivision boundary. Notice that there is some data that will need to be modified such as the township, acreage, and year. This is why it’s important to double-check the defaults when creating the definition file. Nevertheless, it is now easy to make the appropriate changes to all the polylines. Once all the data is added, I can now export out as shape files or other GIS formats to share with others. Another good use of definition files is you can now share the data with the company from which you “stole” the standards and they don’t have to make any changes on their end to make the new data fit in their system. The definition files also prevent extraneous and incompatible data from entering other systems. Andra Marquardt is a Professional Land Surveyor in the State of North Dakota, and has worked for Toman Engineering Company since 1996. She has used AutoCAD beginning with Version 9, and currently uses the latest version of AutoCAD Civil 3D and Map.
Figure 3a: Classify Objects dialog box
36
www.augi.com
December 2013