Sep. 21-22, 2006v FME Worldwide User Conference - Vancouver

Building Polygons – the QA WayBob Janowicz, GIS Innovations, Vancouver, BC

Building Polygons 2

A Simple 6 Zone Map

Starting with aCAD file thatlooks like this

Donuts Y inside Xwith X inside A

Bad line between1 & 2 – double label

(yellow) no label

Label (Z) no area

A

21

YX

Z

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To Build Clean Areas

Lets review this simple workbench

Lines/Polygon Point/Attribute Integration

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4 Phases of Processing

Validate linework Merge lines Unused – unclosed lines

Validate polygons Examine holes and donuts

Extend attribution Validate labels

Areas with NO labels Areas with multi labels Labels with NO areas

A

21

YX

Z

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Building Clean Areas

Line and area (donut) processing

Lines/Polygon

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Clean Linework

Merge Linework

Find Unused Lines A

21

YX

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Trans: Linejoiner

Merge Lines

** Report NON Lines **

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Trans: AreaBuilder

Transformers: AreaBuilder or PolygonBuilder

Treat UNUSED_LINEas a fault – to find/fix

A

21

YX

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Understand AreaBuilder

3 modes Create Donuts/Drop Holes Yes - No - Drop Holes

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AreaBuilder DoNuts

YesCreate Donuts =

No DropHole1:1

Overlaps Drops holes

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Understand PolygonBuilder

Builds each polygon without regard for holes

Can go to DonutBuilder next…

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Understand DonutBuilder

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Admin Zones

One answer for each location AreaBuilder: Create Donuts = YES

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Small Zone Filter

Coast of BC Donut Islands Remove small ones Re overlay

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Getting Labels

Getting the labels then extending and cleaning up the attributes

Point/Attribute

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Get Labels

Get CAD labels – ensure they are text GeometryFilter: keeping only type=text

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Coordinate Attributes

Get Coordinates (curr Projection)

Replicate into new fields (Lat & Long) AttributeReprojector

Reprojects the values in newFields (eg. Lat & Long)

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Attribute Cleanup

AttributeRenamer To adjust names

AttributeKeeper To get rid of

unwanted junkattributes

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Final QA and Polygon

Integrating and QA Areas and Labels

Integration

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Link Labels & Areas

The magic moment Overlaying labels Onto areas NOTE the use of

tracking overlap count

+ X

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Labels w/ NO Area fault

Test the POINT feature to ensure it has one and only one “overlap”

Z

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Labels in Areas Faults

AttributeFilter to test the AREA feature IF overlaps=0 then the area has NO Label IF overlaps > 1 then the area has EXTRA labels

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We Did It

The CLEAN ANSWER IS finally here

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Thank You

Bob Janowicz (president)

GIS Innovations Ltd310-1200 West 73rd Avenue

Vancouver, BC, V6P 6G5bobj@gis-innovations.bc.ca