Autocad Civil 3d Drawing Boats Insert at the Wrong Scale

These instructions apply to AutoCAD® Map 3D® 2013 and newer, and describe how to import georeferenced Nearmap imagery that you've exported with the Export tool in the Nearmap MapBrowser.

Please note that only certain Autodesk applications (AutoCAD Map 3Dand Autodesk Civil 3D) support this functionality. Standard Autodesk packages as well as AutoCAD Plant 3D allow image import but not georeferencing.

AutoCAD will not detect the .jgw georeferencing file if the file path is greater than 128 characters.

These instructions assume that you have already followed the process described in our documentation on exporting imagery, and as a result have downloaded a Nearmap image with an accompanying .jgw file to your computer.

In addition to this document, you can watch our video:

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Step 1 - Prepare Your Files

1. Go to the location to which you downloaded the Nearmap image export.

2. You should find a zip file containing a Nearmap image and .jgw file with similar filenames. If you only have an image, and not a zip file, follow the instructions in our document on exporting imagery and ensure that you select the option to download a georeference file with your image.

3. Unzip the Nearmap download.

4. Make sure that:

   • The path to the .jgw file, including its filename, is up to 128 characters long.

   • The .jpg and .jgw filenames are identical, except for their extensions.

   • The EPSG code (the number after "EPSG" in the filenames of the .jpg and .jgw files) is retained in these filenames, or alternately, you keep a record of this number. You will need to use it soon.

Step 2 - Import the File to AutoCAD Map 3D

1. Open AutoCAD Map 3D. From theHome tab, selectConnect to open theData Connectionswindow.

2. From the list ofData Connections by Provider, selectAdd Raster Image or Surface Connection.

3. Give your connection a simple name.

5. ClickConnect.
   

6. ClickEdit Coordinate Systems.

7. In theSpatial Contexts list, select the first row and clickEdit.
   

8. In theSearch box, enter the EPSG code for the projection in which you downloaded your .jpg. The EPSG code is found in the original filename of the .jpg and .jgw you downloaded from Nearmap.

   • If you downloaded your file inEPSG 3785, enter3857 instead. This is the same projection, but Nearmap uses different naming conventions for it.
     

9. ClickSelect, then clickOK.

10. ClickAdd to Map. Once your image displays, you can close theData Connections window.
    

Note: If you see an Image Insertion window at this point, it means the .jgw world file did not load correctly. Ensure that the .jgw and .jpg filenames match. Also ensure that the filename, including the path, is no longer than 128 characters. AutoCAD  will not detect the world file if its path is too long.

If you need to change the coordinate reference system, continue with Step 3 below.

Step 3 - Reproject your AutoCAD Map 3D Project (if applicable)

If your drawing has in there has no projection assigned, you will need to reproject to a coordinate reference system appropriate for your local area.

Please refer to Natively Supported Coordinate Systems.

If you skip this step your file will not scale properly.

1. Click theMap Setup tab.
2. Click theAssign button.
3. Search for an appropriate local coordinate reference system, and select it.
   (For Australia, projections based on GDA94 are good options; for the US, NAD83).
   
4. ClickAssign.

Your image will probably rotate slightly, indicating that it has been reprojected into your chosen coordinate reference system.

A useful way to check whether your images are displaying in an appropriate projection is to find a circular object on the ground (a roundabout, for example) and verify that it appears as a perfect circle.

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Troubleshooting

Wrong Location

If you open the file and it is in the wrong location, it is likely that the file path is greater than 128 characters. Make sure  that the path to the .jgw file, including its filename, isup to 128 characters long.

Wrong Scale

If you open the file and the scale is wrong, it is likely that you did not reproject your AutoCAD Map 3D project (Step 3). Make sure you assign a coordinate system at the end, otherwise your file will not scale properly.

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Source: https://docs.nearmap.com/display/ND/AutoCAD+Map+3D+-+Importing+Georeferenced+Images

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