CAD-GIS Integration approaches
with ArcGIS
Chris North
ESRI Canada

Key points regarding ESRI’s CAD
support
 ArcGIS CAD data support is core
technology
– ‘Out of the box’
– Does NOT require an extension
 CAD data can be directly read by ArcGIS
– Does NOT require any conversion
– Behavior similar to other feature datasets and classes
 Available at all license levels
 Supported file formats and versions:
– AutoCAD DWG/DXF: Release 12 - 2008
– MicroStation DGN: 5.x – V8

CAD data in ArcGIS
 A vector data source that can be visualized,
queried, analyzed, and converted
 Feature datasets that contain several
feature classes
 Read only data source
 Input datasets for most tools
 Can serve as reference for data creation
– Snapping

CAD data model in ArcGIS
CAD data is comprised of:
Geometry Attributes
ABC
CAD entity geometry is represented CAD properties and database links
as GIS feature geometry are stored in attribute tables
Coordinate
World File
System/Projection
CAD data can be re-projected to CAD drawings can be transformed from
overlay with other GIS layers local coordinates to real-world location

CAD datasets in ArcMap
 CAD feature datasets are
organized into Group
Layers in ArcMap
 Initially in a collapsed
state
 CAD feature layer
properties can be
accessed via the Group
Layer Properties dialog

CAD properties as feature
attributes
 Common CAD
properties
– Color, level, linetype,
handle, line weight, etc…
 User defined
data
– Block attributes
– Tags
– MS-Links
 CAD attributes
support queries
– Display
– Geoprocessing input
– Conversion

Blocks and Cells
3548
 Typically consist of 1 B
multiple Block/Cell
entities/elements and Geometry Feature Class
different geometries
Point
 Can contain text and
attributes 3548, 1, B
Annotation
 ArcGIS represents the Polyline
insertion point as a
point feature Polygon

Tags and block attributes
 Values represented as feature attributes
– Tags = Fields
– Tag values = attributes
 DGN: Tag Sets are not an attribute
DGN DWG

Coordinate Systems and
Projections
 Coordinate Systems
– CAD drawings may not initially
have one defined
– Not required - but recommended
– Select, create or import from
other dataset
 Projection files
– Stores coordinate system info
– Created in ArcCatalog
– Can be copied and reused for
other CAD files

Georeferencing toolbar
 Georeferencing toolbar – use mouse pointer
to move layer and create control points in
map
– Implemented CAD layer support in Georeferencing toolbar
– Leverage existing Georeferencing tools and commands for CAD
transformations

World Files
 World Files
– File based, two point transformation for CAD data
– Uses the .wld file extension
– Simple text file containing two lines with two pairs of
coordinate values:
<From X1, From Y1> <To X1, To Y1>
<From X2, From Y2> <To X2, To Y2>
UC2008 Technical Workshop 11

CAD to Geodatabase Tools
 ArcMap
– Export Data
– Copy & Paste (Edit
session)
 ArcToolbox -
Geoprocessing
– Copy Features
– Feature Class to
Feature Class
– Feature Class to
Geodatabase
– Import CAD
Annotation

Geodatabase to CAD tool:
Export to CAD
 Output features to
native CAD format
– DGN (V8 only)
– DWG/DXF (R14 to R2007)
 Various levels of
complexity
– Geometry only
– Standardized entities
 Preparation tools
– Add CAD Fields
– Add Field

Mapping Specification for DWG
(MSD)
 Open source framework developed by ESRI
for coding information in DWGs to define:
– GIS feature classes + attributes
– Coordinate systems
 Utilizes CAD data structures to define
schema and store data
 Leveraged by ArcGIS CAD tools at 9.3
– CAD direct read/import tools
– Export to CAD
 Provides improved interoperability
between CAD and GIS

Mapping Specification for DWG
(MSD)
 Available in the ArcGIS Online Help system:
– http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?
TopicName=CAD_data_organization

Export to CAD: Creating MSD
compliant DWGs
 Automatically generated by Export to CAD
 Organizes CAD entities into feature classes
in DWG
 Attributes are embedded in CAD entities
 Stores coordinate system in DWG
 Recognized by ArcGIS Desktop at 9.3

Mapping Specification for DWG:
Export to CAD
Output DWG Pre-9.3
Source
Geodatabase
Output DWG @ 9.3

ArcGIS for AutoCAD: Overview
 Provides access to ArcGIS Server map
services
– Control map display
– Identify map feature attributes

ArcGIS for AutoCAD: Capabilities
 Map Services
– Georeferenced
– Projections on-the-fly
– Cartographic GIS
symbology
– Dynamic/On Demand
display
– Scale-dependent
display
– ArcGIS Server data
management
– Database access:
 IDENTIFY map service
features

ArcGIS for AutoCAD + MSD
 Provides ability for
users to
– Read ArcGIS data in CAD systems
– Organize and attribute CAD
drawings for use in ArcGIS
 Solves the question
‘How do I export my
feature attributes to a
CAD drawing?’

MSD Feature Class Tools
 Tools to manage
feature classes in DWGs
– Define, Modify, Delete
 Feature Classes based
on queries
– Entities properties control feature
class participation
 Schema definition
– Add fields

MSD Feature Class Tools
Specify CAD
properties
New
feature
class
name and
type Use property
selectors
Define schema and
default values

THANKS!
Chris North
cnorth@esricanada.com