This document provides instructions for converting contour data from GIS format to CAD format for use in 3D modeling. It involves checking that ArcGIS ArcInfo software is being used, verifying there is a field named "elevation" in the GIS data, and ensuring the data is in a supported projection before using the ArcToolbox Conversion Tool to export the data to DWG or DXF format.

1. GIS to CAD Conversion of Contour Data for Use in 3D
Modeling
1. Check the version of ArcGIS you are running.
To convert GIS data into CAD data you must be using ArcGIS ArcInfo software.
There are three different types of ArcGIS licenses: ArcInfo, ArcEditor and ArcView.
ArcInfo is the highest level of ArcGIS.
a. ArcGIS ArcInfo is only located in GIS Lab in Tisch Library
b. ArcGIS ArcEditor is in all other labs – One copy of ArcInfo will be
available in the CAD Lab in Anderson.
c. You can check the version of software you
are using in ArcMap or in ArcCatalog. To
check the version, go to the Main toolbar and
click on Help About ArcMap (or About
ArcCatalog). This window will popup and
tell you which version of ArcGIS software
you are currently using.
2. Check for “elevation” field in the GIS data.
To convert your GIS Data into CAD data and keep the elevation data within the CAD
file, you must first have a field named “elevation”
a. To check for the “elevation” field while in ArcMap:
i. Right-click on your contour GIS file Open Attribute Table.
ii. A table with all of the fields present in your contour layer will
appear.
iii. The field must be named “elevation” – not “elev” or “elev_ft”. If
you have a field named “elevation” move on to Step 3 – Checking
for a Projection. If not move to Step c.
b. To check for the “elevation” field while in ArcCatalog:
i. Click on your contour dataset while in
ArcCatalog
ii. Click on the “Preview” tab.

2. iii. Change the Preview from Geography to Table.
iv. The Attributes Table will now appear.
v. The field must be named “elevation” – not “elev” or “elev_ft”. If
you have a field named “elevation” move on to Step 3 – Checking
for a Projection. If not move to Step c.
c. To add a field to your GIS dataset:
i. Click on the Options button in the lower right-
hand corner of the Attributes Table.
ii. Go to Add Field
iii. The window to the right will appear. Fill in the
fields as shown and click OK.
iv. Find the existing elevation field in your dataset –
it is probably called something like “elev_ft” or
“elev”.
v. Right-click on the “elevation” field you just created and click on
Calculate Values. You will be asked if it is OK to calculate values
outside of an editing session. Click OK.
vi. The Field Calculator window will
appear. Under the Fields window, click
on the incorrectly named elevation field
(in the example to the right this field is
named “elev_ft”. This will set the
elevation data in the newly created
“elevation” field equal to the
information in the old “elev_ft” field.
vii. Click OK and your “elevation” field will
be populated with the elevation data.
3. Convert GIS files to CAD
• ArcToolbox Conversion Tool To CAD Export To CAD
• Output type DWG _R2000 or DXF_R2000
• Uncheck “Ignore Paths” and “Append to Existing files”
• Do not need seed file
• Must use ArcGIS ArcInfo for this step.