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Question

CAD to GIS

  • 6 February 2013
  • 6 replies
  • 16 views

Below is a question that was posted to the US DoT GIS User community.  I thought that the FME Community may be able to provide some insight:

 

 

Hi all,

 

 

We have some projects going right now working to harvest CAD data to feed our growing enterprise asset management system.  We are running into issues with being able to carry some sort of identifier for each feature (culvert, sign, etc.) coming out of a design plan and into a database where we can add addition business data without manual editing.

 

My questions are twofold. First we are looking to talk to any of you that have a process where Microstation users can push a button that kicks off a process using FME (or any other kind of macro) to pull information out of CAD and into Oracle or SQL. 

 

 

Second, we would like to be able to attach/imbed some sort of feature ID/key to a feature in Microstation that can be extracted into a table with that feature geometry and used as a key field to attach to a table with business data.  We have a solid storage process for our project files and a pretty rigorous level management happening in the Microstation files and have been able to successfully pull data out of CAD and into other formats but we really need a way to attach a ID/key or one or two pieces of business data to the feature as it is drawn into the plan and then extract that ID with the feature.

 

 

I hope that makes sense am happy to go into detail with any of you who are making some headway in the CAD to GIS (or to enterprise database) processing. We are looking for and hope you can provide us with some insight. 

 

Thanks 

 

Shawn

 

 

Shawn Blaesing-Thompson, GISP

 

Maintenance GIS Coordinator

 

Iowa Department of Transportation

 

Office of Maintenance

 

800 Lincoln Way

 

Ames, IA 50010

 

 

Drew,

 

This is very much possible to achieve using FME using MSLINK concept.

 

For linkage between a table in MSAccess or Oracle or SQL Server, MicroStation requires MSLINK attached to graphics in the dgn and the same value stored in the table under MSLINK in the database to be able to extract the attribute information from the database for the graphical element.

 

Once MSLINK is available for graphical elements of interest it would be easy to attach additional business data.

 

It would be interesting to understand the data model to explore what best way the additional business data can be attached with reference to the feature ID or Key ID.

 

Happy FME-ing :-)

 

SRG
To elaborate on SRG's otherwise excellent reply: Depending on your CAD system, there might be two MSLINK values for each object, the first referencing the feature type (or layer) and the second as the unique identifier within each feature type.

 

 

Using the FME Universal Viewer it might look something like this:

 

 

MsLink-DMRS          5163

 

MsLink-DMRS 1       2233

 

 

Where 5163 denotes a specific feature type (or layer) and 2233 uniquely identifies the object within this feature type.

 

 

Note that it is very much possible to have unlinked objects (objects with no MSLINK) and that you might need to be able to handle these in some way.

 

 

Good luck!

 

 

David
I have done some CAD to GIS workflows and can provide some more information if you like but I would be interested in seeing the data model and getting an idea of what additional business data you are attaching.

 

 

For the unique id, I think you could use the autocad_entity_handle and link that with the drawing name to create an idea that can be ported to the GIS and then extracted and tied back to the CAD drawings.
Clearly I don't have an answer since it was my question to begin with.  So in Microstation what does the process look like to set up these MSLINK processes?
Hi Shawn,

 

 

I'm guessing that you should be able to find more information regarding how to set up the MSLINKs in the Microstation forum, or through your regular Bentley support channels.

 

 

David
Hi, Another option would be to have a Design File Tag attached to a feature (similar to Object Data in AutoCAD) where you can populate the unique key  and it is more readable. FME can read  Microstation Tag.

 

Zubair

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