AutoCAD Map: Speaking the Same Language
In an international world, where good communication is necessary, the ability of software to “speak” different languages—specifically to import and export multiple file formats—is crucial.
AutoCAD® Map handles this well. The software can import and export ArcGIS shape files and coverages, Microstation, and MapInfo, to name a few.
With more companies moving to GIS systems, it’s imperative for companies to implement their own GIS, or at least create the ability to not only view but manipulate data provided by other companies or government agencies. Map is versatile enough to create and manipulate data based on a company’s unique needs.
Typical Scenario – Using City GIS Systems
The City of Bismarck in North Dakota has put together a robust GIS system of the entire city, including some parts of Burleigh County. Even better, all the data is made available to the public in ArcGIS shape files. They are organized first by data type such as land base (subdivisions, lots, blocks and address points), water, sanitary sewer, electrical, storm, topography, and image files. For private engineering and land survey firms, the data is not only useful, but saves a tremendous amount of research time (see Figure 1).
Figure 1: City of Bismarck’s public GIS FTP site.
Once we decide what data we need, it’s now a matter of deciding how to import it.
Using Map Import
The quickest way to import shape files is with Map Import (Insert Tab on the Ribbon Map Import or type MAPIMPORT). Using this method, you can import multiple shape files at once. The benefit is time savings, because you’re not importing data one type at a time. It’s also useful for those who have AutoCAD® standard or AutoCAD® LT, and still need access to the linework of some data.
Another benefit to this method is the ability to determine how much data to bring in from the shape file (see Figure 2).
Figure 2: Using Map Import
If you only want the linework, you can choose not to import any attribute data. Or you can choose the “Create object data” option. I usually choose this option, because as a surveyor and engineer, I’m equally interested in the data as well as its location.
The one downside to this method is you can’t search for specific data such as a manhole type or subdivision. All you can do is pick it and view the data within Properties (see Figure 3).
Figure 3: Viewing imported data
Although the data is included in the AutoCAD entities, it is not linked to the original shape files. Therefore, any changes you make to the linework or properties will not be updated. This could be a good thing, because someone working in the AutoCAD file cannot inadvertently make changes or deletions to the original data.
Using Data Connect
When it comes to being able to search data, especially within larger areas, using Data Connect is a better option.
Often we are hired to survey a specific lot in a subdivision, but sometimes we don’t know exactly where it’s located.
For example, by bringing in the Subdivision and Lot shape files, I can bring up the data table (Task Pane -> Right-Click on Feature -> Show Data Table), and organize by column in ascending or descending order. I can also create a calculation or filter out specific data. Once I find what I’m looking for, all I need to do is double click on the gray box to the left of the table. Map will zoom in and highlight the feature I need (see Figure 4).
Figure 4: Using Data Tables.
By using Data Connect, you can also modify or add any features, and the shape files will be updated. For instance, if we created a new subdivision within the City of Bismarck, instead of waiting for their GIS to be updated and uploaded to the FTP site, we can add it to our system.
Exporting Data Connected Features
When working with shape files you might encounter a situation in which someone within your company or a different firm needs the same data, but has only AutoCAD. You could start another drawing and import using Map Import, but if there is a lot of data, that would take a considerable amount of time.
A better way is to Save Current Map to AutoCAD in the Output tab of the Ribbon (command MAPTOACAD). Note to AutoCAD® Civil 3D® users: Both the ribbon and typed command will give you an “Unknown command” error. Instead type MAPEXPORTCURRENTMAPTODWG. (How’s that for a lengthy command?)
The drawing it creates now has all the linework, polygons, and symbols of the original drawing, but without the feature data (see Figures 5 and 6).
Figure 5: Connected data
Figure 6: Exported drawing file
The difference is all the linework are polylines. Polygons are closed polylines with hatches, and any symbols are basically exploded into their basic parts, such as lines and circles.
Creating a Simple GIS
My firm was recently hired by a small town about 30 miles outside of Bismarck to create a GIS system similar to Bismarck’s. We showed them what Bismarck did with theirs, and they decided that’s exactly what they wanted.
They also asked for our recommendation of software to view and manipulate the data once it was created. We went back and forth between AutoCAD Map and ArcGIS. Eventually we decided on ArcGIS, because it was designed for GIS, not drafting. AutoCAD Map would have too large of a learning curve for the city. However, we did decide to create their system using Map, because we were already familiar with the software. And with our experience using Bismarck’s system, exporting out to shape files was fairly simple. The most time-consuming portion of building the system was compiling all the data and deciding what to include. Luckily we had surveyed most of the city and had all the data in an AutoCAD file using Civil 3D. From there it was a matter of creating Object Classes for each type of data such as storm sewer manholes and street lights.
Once we had all the data compiled into Map including Internet links to tax data and an Excel file of all parcel ownerships, all we have to do now is export ESRI Shape files using Map Export (under the Output Tab). Using ESRI’s ArcGIS, all the city has to do is attach the shape files, create a link to the Excel file, and they are ready to roll.
There were other ways to create a system that would be more robust, secure, and efficient than shape files, but for a small city just starting out using GIS, it was the best option.
In the end it’s about communicating data across a variety of software platforms made available to multiple companies and governmental agencies. Whether using AutoCAD, Microsoft Excel, or ESRI’s ArcGIS, it is crucial that the software communicates as seamlessly as possible in today’s information age. AutoCAD Map makes that happen.