Issue when importing SHP files using GEO coordinate systems

[Anonymous]

I am trying to import some shapefiles for a master road network comparison. The issue is that the shapefiles i got don't recognize a coordinate system when trying to import them. When I do import them they're scale and position is way off for what I need them to be.  The agency that sent me the shapefiles sent me a screenshot of they're data source (screenshot attached) and I could not find the coordinate system from the data source in my civil 3d coordinate system list. I know they used ARC GIS to create they're but this is the first time i ran into an issue with shapefiles and I'm guessing they're are different steps I need to take in this situation, I just have no clue on what they are. Any help would be very much appreciated.

Civil 3D Coordinate system: NAD83 Texas State Planes, Central Zone, US Foot (TX83-CF)

Civil 3D Units: Feet

[Mike.M.Carlson · Accepted solution]

Hello-

Your coordinates in your .shp file are Geodetic (lat / longs) or in terms of the GRS80 ellipsoid.  That is the datum used for NAD83 state plane mapping projections.  Do you have ArcGIS?  It's easiest to "project" the .shp to the mapping projection you're working in C3D.

I hope this helps.  

[Anonymous]

Unfortunately no.

[Mike.M.Carlson]

Please attach the .shp files in a .zip and I will be happy to convert it for you.

[Anonymous]

But based on your response it seems like it would be way easier and less headaches and request for the agency that sent me the shapefiles to do the projecting for me.

[Mike.M.Carlson]

Yes you're right.  It takes 5 mins for me to do it...up to you if you want to wait 🙂

[Anonymous]

I attached the zip files. Thanks so much Mike.

[Mike.M.Carlson]

The option to try in C3D is to use the Map 3D Connect option to connect to the .shp.  You will do this in the dwg where you have the Texas State Plane Coordinate system defined.   When you connect to the .shp, you can specify the incoming coordinates system of the .shp as shown below:  You will want the Lat / Long catagory and choose NAD83 Datum Lat-Long.

[Anonymous]

Ok I will use that method. What is the difference between the Map3D connect feature and the MAPIMPORT command? If I am not mistaken I believe when you do MAPIMPORT and put an input coordinate system it takes you to the same place where you choose the coordinate system.

[Mike.M.Carlson · Accepted solution]

Here is the "Projected" .shp bundle.  

MAPIMPORT doesn't handle .shp files that are based solely on geodetic (lat/long) data for some reason.  That command does great with .shp files that are based on a mapping projection.   

Map 3D Connect seems to handle these transformations better.  Sometimes it doesn't work, but lately I have found that it works, so try it out.  If it doesn't work the attached .shp will work.

Good luck. 

[Anonymous]

I will definitely give that a try. Thanks for all your advice and help Mike. Very much appreciated.

[Pointdump]

Victor,

I think the only problem with your Shapefile Data is the PRJ file. Map 3D doesn't recognize that ArcGIS-created PRJ. So from <<<This Site>>> grab the PRJ for EPSG:4269 and then replace the text and save. Then you can Drag-n-Drop(Same as _MAPCONNECT) that shapefile into a TX83-CF Drawing. (I've attached the PRJ file you need.)

Dave

[ChicagoLooper]

Geo lat/lon coordinates can indeed be used with MAPIMPORT. I do this frequently when I want to bring in a shapefile as an AutoCAD entity. By doing this, I can then control the vectors, i.e. points, lines or polygons, directly through Cad. Layers, colors, line type, line weight, all can be manipulated in Cad as opposed to the maptaskpane. The key is to first assign a coordinate system to modelspace and, if needed, assign a second coordinate system to the shapefile being imported. Map 3D will transform the shapefile's CS to be in harmony with modelspace's CS. Of course, knowing which CS to assign to the shapefile and to modelspace is key to harmonization.

Notes:

1. This demo uses Planning and Analysis workspace. (If you're in Civil 3D you'll need to switch to P and A.)
2. To ascertain State Plane, I first imported the shapefile without any CS assigned and looked at a single point's x/y values. The values were in the neighborhood of x=30.26 and y=-97.74. Using years of experience, these values appear to be lat/lon's and doing a quick search, placed the point in Austin, Texas in Travis County. Another search indicated Travis County is in Texas Central Zone. Using US feet as the projected units, it is TX83-CF, or EPSG 2277.
3. To maintain the tabular data native to the shapefile, you can create 'object data' during the import process. This will bring in the attribute data and can be seen by scrolling to the bottom of the Properties palette after clicking on an imported entity.

[ChicagoLooper]

The 'unrecognized' prj can be edited to a known coordinate system. This is, of course, assuming you already know what the coordinate system should really be.

If the CS is 'unknown' then you can edit the CS to the correct one.

[Mike.M.Carlson]

I didn't realize you can edit the incoming coordinate system in MAPIMPORT command dialog.  As I described above, I thought this was only possible with the Map 3D Data connect option.  Great tip thanks!

[Mike.M.Carlson]

Where are all the other more recent NAD83 realizations in the CS dialog? I see two default NAD 83 options, which I assume relate to the NAD83 (1986) realization? I also see the HARN version, which is kind of old (early 90’s). What about the NAD83 (2007, 2011 epochs)? Without these, it will be hard to match output from ArcGIS if certain .shps are exported with more recent NAD83 realizations.

I see there are State Plane mapping projections with these NAD83 distinctions. I wonder how C3D accounts for these in the projection side?

[ChicagoLooper]

I agree, it's not always easy to figure out how to access a desired datum especially across different programs. Map 3D's is Autodesk's 'diamond in the rough' and it's too bad it's not promoted for being as powerful as it is.

Try this: Map Setup tab=>Coordinate System Panel=>Assign button. In the 'search box' try entering different parameters.  Here are some examples :

1. For State Plane try these TX83 = Texas, CA83 = California, IL=for Illinois etc.
2. For lat/lon 1983 datum = LL83
3. For WGS84 = LL84
4. For NSRS 2007 = 2007
5. For NSRS 2001 = 2011
6. If you know the EPSG code, type the code directly into the search box.

While in the Coordinate System-Assign dialog box, you may highlight a CS, then click 'View' instead of assign. In the left side panel of the next dialog, click -WKT and you'll see the nitty-gritty behind the CS.