© 2011 Autodesk Understanding the Alignments and Profiles API in AutoCAD® Civil 3D® Isaac Rodriguez Sr. Software Engineer.

© 2011 Autodesk

Understanding the Alignments and Profiles API in AutoCAD® Civil 3D®Isaac RodriguezSr. Software Engineer

© 2011 Autodesk

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About the Presenter

Isaac is a senior software engineer at Autodesk, and current software development lead of the AutoCAD® Civil 3D® API. Isaac has been with Autodesk for almost eleven years working in different products and technologies like AutoCAD Raster Design and AutoCAD Civil 3D. He has 20 years of software development experience including six years with Microsoft® .NET technologies.

Contact me through email: [email protected] me on Twitter: @CivilDevRead my blog: http://civilizeddevelopment.typepad.com

© 2011 Autodesk

About the Audience

Tell me a little bit about you.

• Software Development implementing Civil 3D applications• Civil Engineer writing automation scripts and internal tools• Are you using .NET?• Which .NET language you prefer?

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Class Summary

This class covers the basics of the Alignments and Profiles .NET API in Civil 3D. It also dives into the structural components of Alignment and Profile objects and their composition. Finally, the class demonstrates how Alignments and Profiles can be manipulated by changing parameters in their components.

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Learning Objectives

At the end of this class, you will be able to: Understand the structure of the Alignment and Profile objects Access to Alignment and Profile entities through the API Working with Alignment and Profile Entities according to their type Working with Alignment and Profile Entities and their constraints Complete the C3D API Challenge!!!

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Structure of Alignment and Profile Objects

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Alignments and Profiles

Two dimensional, linear objects Composed of other two dimensional, linear objects (Entities) Alignments represent different model features Profiles represent elevation points along an Alignment Structures are similar but representations are different

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Alignment Structure

Alignments contain Entities Entities contain Sub-Entities Sub-Entities different from Entities

Alignment

Entity

Sub-Entity

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Alignment Entities

Entities have a type Type identified by EntityType property (AlignmentEntityType enumeration) Object class does not identify entity type

Basic Entities contain 1 Sub-Entity Composite Entities contain 2 or more Sub-Entities Entities have constrains

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Basic Alignment Entities

Contain a single Sub-Entity Lines (Tangents), Arcs (Curves), and

Spirals

Entity Entity Class Entity TypeLine (Tangent) AlignmentLine LineArc (Curve) AlignmentArc CurveSpiral AlignmentSpiral Spiral

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Composite Alignment Entities

Entity Entity Class Entity TypeSpiral-Curve-Spiral AlignmentSCS SpiralCurveSpiralSpiral-Line-Spiral AlignmentSTS SpiralLineSpiralSpiral-Line AlignmentSTS SpiralLineLine-Spiral AlignmentSTS LineSpiralSpiral-Curve AlignmentSCS SpiralCurveCurve-Spiral AlignmentSCS CurveSpiralSpiral-Spiral-Curve-Spiral-Spiral AlignmentSSCSS SpiralSpiralCurveSpiralSpiralSpiral-Curve-Spiral-Curve-Spiral AlignmentSCSCS SpiralCurveSpiralCurveSpiralSpiral-Curve-Spiral-Spiral-Curve-Spiral AlignmentSCSSCS SpiralCurveSpiralSpiralCurveSpiralSpiral-Spiral (*) AlignmentSCS or AlignmentSTS SpiralSpiralSpiral-Spiral-Curve AlignmentSSCSS SpiralSpiralCurveCurve-Spiral-Spiral AlignmentSSCSS CurveSpiralSpiralCurve-Line-Curve AlignmentCTC CurveLineCurveCurve-Reverse Curve AlignmentCRC CurveReverseCurveCurve-Curve-Reverse Curve AlignmentCCRC CurveCurveReverseCurve

Entity type MultipleSegments not used nor supported(*) AlignmentSCS used if entity between two lines and AlignmentSTS used if entity between two curves

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Profile Structure

Profiles contain Entities Profile Entities are Simpler

Lines (Tangents) Arcs (Circles) Parabolas

Symmetric Asymmetric

Entities have constrains

Entity Entity Class Entity TypeTangent ProfileTangent TangentCircular ProfileCircular CircularParabola Symmetric ProfileParabolaSymmetric ParabolaSymmetricParabola Asymmetric ProfileParabolaAsymmetric ParabolaAsymmetric

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Accessing Alignment and Profile Entities

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Entities Collection < IEnumerable >

Accessed through Entities property Interface to access entities Implements IEnumerable for

AlignmentEntity Entities enumerated by ID ID depends on alignment creation

Time for some Code

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Entities Collection < EntityAtId() >

FirstEntity and LastEntity provided by collection

EntityBefore and EntityAfter provided by AlignmentEntity

EntityAtId() retrieves entity Suitable for sequential and direct

access

Some More Code

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Alignment Entities Collection < GetEntityByOrder() >

Zero-based index Less-than Count property value Raises exception with unconnected

entities Not suitable for enumeration Use for direct access

And More Code

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Working with Entities based on Type

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Alignment and Profile Entities by Type

Entities have a type Leads to complex logical code Prefer abstractions and polymorphism

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Entity Abstractions

Create you own entity wrappers Separate wrapper creation from processing Provide interface related to requirements Use virtual functions for specialized functionality (polymorphism)

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Function Objects (Functors)

Objects that work like functions Flexible and highly customizable Represent application processes

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Implementing ‘ExportAlignment’ Command

Function Object to export information Customizable order Customizable output target

Entity wrappers responsible for own information Logic to identify entity in Factory class

Let’s look at some code

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Working with Entities Constraints

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Constraint Types

Tangency Constraints Relation between entity and surrounding entities Common to all entities

Entity Definition Constraints Specific to an entity Represent how entity was defined (during creation)

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Tangency Constraints

Relation between entity and surrounding entities Common to all entities

Free / Fixed / Float on Previous / Float on Next Only editable in Alignments feature Not editable through the API They may affect the entire Alignment/Profile object

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Definition Level Constraints

Specific to an entity type Represent entity definition Indicate which parameters can be modified

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Recommendations Working with Constraints

Separate logical code from process Use “Strategy Pattern” for processing algorithms Evaluate constraints to decide strategy

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Strategy Pattern

Behavior defines interface Context provide point for

customization Concrete implementations of

interface Decide who customizes behavior

Let’s Look at some code

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Summary

Alignment and Profiles Linear objects composed by entities Different interfaces to access entities

Provide your own entity abstractions (wrappers) Implement process as Functors (Function Objects) Separate logical code from processing code Centralize logic (Decision methods / Factory methods) Provide customization of behavior (Strategy Pattern)

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Questions?

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C3D API Challenge

Reinforce the topics of this class Have fun with them Featured in Civilized Development Details in materials handout Submit entries prior December 31st 2011

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Autodesk, AutoCAD* [*if/when mentioned in the pertinent material, followed by an alphabetical list of all other trademarks mentioned in the material] are registered trademarks or trademarks of Autodesk, Inc., and/or its subsidiaries and/or affiliates in the USA and/or other countries. All other brand names, product names, or trademarks belong to their respective holders. Autodesk reserves the right to alter product and services offerings, and specifications and pricing at any time without notice, and is not responsible for typographical or graphical errors that may appear in this document. © 2011 Autodesk, Inc. All rights reserved.