harness the power of auto cad map and esri

© 2009 Autodesk

Harness the Integrated Power

of AutoCAD Map 3D & ESRIAutodesk Interoperability Tools

Richard E ChappellGeospatial Application Engineer

© 2009 Autodesk

Welcome

Richard Chappell – “Rick”Geospatial Application Engineer

[email protected]

http://www.cadsoft-consult.com/blogs/geo/

http://www.linkedin.com/in/richardchappell

Janelle RamosGovernment Account Executive

[email protected]

CADsoft Consulting, Inc

1295 W. Washington St., Suite 201, Tempe, AZ 85281

480-820-0408

mailto:[email protected]










© 2009 Autodesk

Objective

Clarify the CAD to GIS discussion

Understanding of the Autodesk tools for interoperability

© 2009 Autodesk

Agenda

Identify the problem

Review the technologies

Look at solutions

Practice the solutions

© 2009 Autodesk

Ground Rules

No religious discussions

No discussion of whether GIS or CAD is better.

Many of us, for various reasons, need to work in

an environment shared between CAD and GIS

software

© 2009 Autodesk

CAD and GIS Myths

CAD is dumb data

GIS is not accurate

CAD drawings aren’t “clean”

CAD doesn’t use coordinate systems

CAD uses x and y coordinates, and GIS uses Latitude and Longitude

CAD is a graphics program and GIS is a database program

You can’t do analysis with CAD programs

Technology now allows us to capture 80% of CAD data for GIS

Moving data between CAD and GIS is difficult

© 2009 Autodesk

CAD and GIS Basics

Both consist of basic primitive elements

Points

Lines

Polygons

Attributes

Both store this information within a database

© 2009 Autodesk

Points

Represent a position or location

Consist of coordinates – X, Y and Z

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Lines

Consist of coordinate pairs – a start point

and end point

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Polygons

Consist of group of coordinate pairs – a

boundary of lines

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Complex Features

Complex features are generally some

construct of these primitives

Annotation is a form of point

Polylines are groups of lines

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Attributes

Primitives will have data elements attached

Some elements describe the object itself

Some are data describing what the object

represents

© 2009 Autodesk

So what is the difference?

Data Structure Paradigm

Graphic Representation

© 2009 Autodesk

Data Structure Paradigm - AutoCAD

AutoCAD stores data in a free form object

oriented database where the fields in each row

are defined by the entity type

DWG File

Entity ID Line St Point End Point Layer

Entity ID Point Point Layer Color

Entity ID Block Ins Point Layer Color

Entity ID Arc St Point End Point Bulge

© 2009 Autodesk


ArcGIS stores data in predefined data structures

where the fields are defined in each data type

Feature Class (Pipes – Lines)

ID Shape (BLOB) SIZE MATERIAL IN USE

ID Shape (BLOB) SIZE MATERIAL IN USE

Feature Class (Vegetation – Polygon)

ID Shape (BLOB) SPECIES AGE AVG DBH

ID Shape (BLOB) SPECIES AGE AVG DBH

© 2009 Autodesk

AutoCAD Points

© 2009 Autodesk

AutoCAD Lines

© 2009 Autodesk

AutoCAD Polygons

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AutoCAD Point Data Set with Attributes

© 2009 Autodesk

ArcGIS dataset

© 2009 Autodesk

What this means

The means that AutoCAD will store multiple

data types in a single DWG, while ArcGIS

will store multiple data types in separate

tables and/or files

Tables in Geodatabase

Sets of files for Shapes and other formats

© 2009 Autodesk

Graphic Representation

In AutoCAD, the graphic representation is

stored on the object as part of the individual

object definition

In ArcGIS, all graphic representation is kept

separate from the data

© 2009 Autodesk

What this means

Sharing a DWG file provides an exact

representation of the original graphic

representation

Sharing a GIS data set will not provide an

exact representation of the original graphic

representation, without the ancillary

support files

Not good or bad – just different

© 2009 Autodesk

Other Differences

Coordinate number data types

Floating point vs Long Integers 32-bit

Single vs Double Precision

Some differences in primitives

Annotation – feature linked as well as annotation

objects

Curves – curve data isn’t carried through some

GIS data sets

© 2009 Autodesk

Curves from a Shapefile

© 2009 Autodesk

What’s The Point

The physical transfer of data is a minor

technical issue

Most software vendors now provide excellent

tools to transfer data back and forth

Most will allow direct editing of other data

formats

© 2009 Autodesk

So What’s the Problem?

© 2009 Autodesk

How it is seen in GIS

© 2009 Autodesk

Integration Barriers

The primary barriers to integration are data

organization and business issues rather

than technical issues

The purposes of the data have a much larger

impact than how the data is stored

Understanding those issues can remove the

barriers

© 2009 Autodesk

Purpose of the Data

The purpose of the data can have a profound

impact on the data

Across the facility management environment,

there are a number of areas of the lifecycle,

each with its own requirements

© 2009 Autodesk

Let’s take a look

at some of the tools

and methods

© 2009 Autodesk

Interchange

Convert and share data files

AutoCAD Map Import

ArcMap Geoprocessing

FME Safe Software

© 2009 Autodesk

Interface

Pass data between systems

ArcGIS for AutoCAD - ESRI

GISConnect – Haestad Methods

Bentley

Crossfire* - EMS

© 2009 Autodesk

Integrate

Use the same data

AutoCAD Map’s Feature Data Objects (FDO)

Crossfire* - EMS

© 2009 Autodesk

Interchange – Methods

AutoCAD Map Import – Creates AutoCAD objects with attributes

© 2009 Autodesk

Map Overview

© 2009 Autodesk

Try It – Map Import

© 2009 Autodesk

Interchange – Methods

AutoCAD Map Export – Creates shape file with data elements as

attributes

© 2009 Autodesk

Try It – Map Export

© 2009 Autodesk

Integrate –Methods

Feature Data Objects (FDO)

Open Source Connectors – provider determines capabilities

Not conversion or import – reads the data directly

© 2009 Autodesk

Try It – FDO Connections

© 2009 Autodesk

Try It – Edit and Add Data

© 2009 Autodesk

Try It – Create a Shape File

© 2009 Autodesk

Purpose of the Data

The purpose of the data can have a profound

impact on the data

Across the facility management environment,

there are a number of areas of the lifecycle,

each with its own requirements

© 2009 Autodesk

Scale

Different scales have different requirements

Generally, design scales will be much larger

than GIS map scales – Design scales get in

the 1”=20’-50’ range, where system maps

get much smaller, as in 1”=100’-400’

© 2009 Autodesk

Generalization

Reduce complexity by

Grouping of similar objects to simplify an image

Simplification of lines based on scale

Feature coalescence, selection and complexity

reduction

© 2009 Autodesk

Granularity

Granularity is the grouping of dissimilar

objects to represent a single feature

Items that aren’t important to the operation of

the system may be dropped from facility

maps

© 2009 Autodesk

Precision and Accuracy

Higher accuracy is more expensive

Design requires a high degree of accuracy

Underground utilities

Most new construction work will include a

site survey of 3rd order (or close) to identify

the existing conditions

With a large land base, highly accurate data

is likely too expensive to create and

maintain

© 2009 Autodesk

Cartographic Issues

Symbols

Blocks vs Fonts

Linetypes and masking

Appearance – White Space

“Slackuracy”

© 2009 Autodesk

Standards

Freeform nature of AutoCAD allows great

flexibility

We can constrain CAD data to a similar

organization as GIS through standards

© 2009 Autodesk

Layers

In AutoCAD, layering is the most common method of

segregating data

In ArcGIS, feature classes and subtypes define

segregate the data

Match layers to feature classes and subtypes to

segregate the data

Use similar object types within each layer

ie. Lines with lines, points with points

© 2009 Autodesk

Point Symbols

Represent points in data set

ArcGIS uses a font in the map document to

create the symbol

AutoCAD would use a block in the drawing

Identify Font-Block Mappings during

conversion

© 2009 Autodesk

Geometry

Maintain snapping through connected line

features – use wipeouts to mask lines

Insure intersections are broken within a

single data set

Use closed polygons to identify polygons

© 2009 Autodesk

Attributes

Use attributes to label items rather than text

labels

Use label blocks to attribute polygons and

lines – after conversion, they can be

spatially joined

One label block per element

Consider using external database links and

maintaining an ID as an attribute

© 2009 Autodesk

Conclusion

By understanding the issues that really impact our

processes, we can develop workflows that will allow us to

take the most advantage of our data

© 2009 Autodesk

Thank-You!

Rick ChappellGeospatial Application EngineerCADsoft Consulting, Inc1295 W. Washington St., Suite 201, Tempe, AZ 85281480-820-0408 [email protected]://www.cadsoft-consult.com/blogs/geo/http://www.linkedin.com/in/richardchappell

www.cadsoft-consult.com

Interoperability Training – July 29








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