CAD to GDB tool, outputs exist in different spatial extent

[WarrenDavison]

Hi,

I'm trying to use the 'Import from CAD, to Geodatabase' tool from the Conversion Toolbox. I've encountered issues where the results of this tool are not where they should be (on top of the input CAD drawing).

In ArcMap I have georeferenced the input CAD dataset and saved the updated world file as specified in the Desktop Help.http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Transforming_CAD_datasets

Although after completing these steps and defining the coordinate system and projection and attempting to execute the tool again the results continue to appear at the wrong coordinates. This result is inconsistent as other CAD datasets I have converted with this tool appear in the correct output extent, leading me to believe there is some variance with the CAD data. I am no CAD expert, but I thought this inconsistency, in spatial reference and coordinates, would have been rectified through georeferencing in ArcMap.

Is there something I am overlooking in the original CAD dataset spatial information that could be causing this problem?

Thanks in advance,

Warren

[WarrenDavison · Accepted solution]

This issue has been resolved,

After investigating, the 'Import to GDB from CAD' tool reads the spatial references from the source CAD dataset and does not take note of the peripheral files created during the georeferencing session within ArcMap (.world, .prj, etc...).

I have yet to find a work-around to this.

[CoreyLunsford]

I'd like to see this answered. I am having the same exact problem and am ready to chuck my computer out the window.

[WarrenDavison]

I'd like to see this answered. I am having the same exact problem and am ready to chuck my computer out the window.

Hi Corey,

After posting this I did some experimenting with the CAD to GDB tool and found that the way the tool is designed to function restricts it to "reading" the spatial reference from the CAD file only. Therefore, even though you may georeference the drawing within an ArcMap session and click 'update georeference' the outputs of the CAD to GDB tool when using this CAD drawing will always appear in the middle of nowhere. This is because the .world file or .prj file created from updating the georeferencing are saved as separate files and are not captured by the CAD to GDB tool.

That would explain why when the drawing is added to an ArcMap session after being georeferenced it appears where it should, but when used as an input into the GDB tool the outputs appear out in space.

I was able to come up with 2 alternatives:
1. Add the CAD drawing to your ArcMap session and georeference it then convert it to layers by right-clicking the drawing in the table of contents window. This will preserve the spatial reference you have created through georeferencing and allow you to utilize the features.

2. The second option involves AutoCad, if you have the software available it is possible to georeference it to a dataset that has a correct spatial reference through a few simple steps. I have documented these steps which may prove useful to you if this is a viable option, this can then be used to create the GDB using CAD features.

[BillMacPherson]

2. The second option involves AutoCad, if you have the software available it is possible to georeference it to a dataset that has a correct spatial reference through a few simple steps. I have documented these steps which may prove useful to you if this is a viable option, this can then be used to create the GDB using CAD features.

WarrenDz,

If you could post the steps for correcting the spatial reference in AutoCAD, it would be very helpful.

[ScottBurton]

Warren,

I would also be interested to learn your workflow for getting CAD properly projected. We're having a heck of a time with a new Trimble device going from C3D to the device, and as the only resident GIS "expert", I'm tasked with creating properly projected .shp in Arc and exporting to the Trimble. Might be easier. Think I've figured it out but I'd like to see how others are doing it. Thanks!

[WarrenDavison]

WarrenDz,

If you could post the steps for correcting the spatial reference in AutoCAD, it would be very helpful.

Hi Bill,

Essentially the way I solved the georeferencing issue with the CAD file was to:
1. Export a reliable spatial reference from GIS to CAD (ex. parcel fabric feature class).
2. I then added this to my CAD drawing file within AutoCAD and used a combination of the scale, move, rotate function to "georeference" the existing CAD drawing to match to my newly added CAD version of my parcel fabric
3. The drawing (.dxf/.dwg) then needs to be exported and saved via the AutoCAD software and added back into your ArcMap project

Hopefully this gives you a general idea of how to go about solving your referencing issue.

Warren