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

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3. 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.
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4. 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?

5. 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.

6. 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!!!

7. Structure of Alignment and Profile Objects

8. 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

9. Alignment Entity Sub-Entity Alignment Structure
Alignments contain Entities
Entities contain Sub-Entities
Sub-Entities different from Entities
Alignment
Entity
Sub-Entity

10. 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

11. Basic Alignment Entities
Contain a single Sub-Entity
Lines (Tangents), Arcs (Curves), and Spirals
Entity
Entity Class
Entity Type
Line (Tangent)
AlignmentLine
Line
Arc (Curve)
AlignmentArc
Curve
Spiral
AlignmentSpiral

12. Composite Alignment Entities
Entity
Entity Class
Entity Type
Spiral-Curve-Spiral
AlignmentSCS
SpiralCurveSpiral
Spiral-Line-Spiral
AlignmentSTS
SpiralLineSpiral
Spiral-Line
SpiralLine
Line-Spiral
LineSpiral
Spiral-Curve
SpiralCurve
Curve-Spiral
CurveSpiral
Spiral-Spiral-Curve-Spiral-Spiral
AlignmentSSCSS
SpiralSpiralCurveSpiralSpiral
Spiral-Curve-Spiral-Curve-Spiral
AlignmentSCSCS
SpiralCurveSpiralCurveSpiral
Spiral-Curve-Spiral-Spiral-Curve-Spiral
AlignmentSCSSCS
SpiralCurveSpiralSpiralCurveSpiral
Spiral-Spiral (*)
AlignmentSCS or AlignmentSTS
SpiralSpiral
Spiral-Spiral-Curve
SpiralSpiralCurve
Curve-Spiral-Spiral
CurveSpiralSpiral
Curve-Line-Curve
AlignmentCTC
CurveLineCurve
Curve-Reverse Curve
AlignmentCRC
CurveReverseCurve
Curve-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

13. Profile Structure Profiles contain Entities
Profile Entities are Simpler
Lines (Tangents)
Arcs (Circles)
Parabolas
Symmetric
Asymmetric
Entities have constrains
Entity
Entity Class
Entity Type
Tangent
ProfileTangent
Circular
ProfileCircular
Parabola Symmetric
ProfileParabolaSymmetric
ParabolaSymmetric
Parabola Asymmetric
ProfileParabolaAsymmetric
ParabolaAsymmetric

14. Accessing Alignment and Profile Entities

15. 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

16. 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

17. 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

18. Working with Entities based on Type

19. Alignment and Profile Entities by Type
Entities have a type
Leads to complex logical code
Prefer abstractions and polymorphism

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

21. Function Objects (Functors)
Objects that work like functions
Flexible and highly customizable
Represent application processes

22. 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

23. Working with Entities Constraints

24. Constraint Types Tangency Constraints Entity Definition 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)

25. 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

26. Definition Level Constraints
Specific to an entity type
Represent entity definition
Indicate which parameters can be modified

27. Recommendations Working with Constraints
Separate logical code from process
Use “Strategy Pattern” for processing algorithms
Evaluate constraints to decide strategy

28. Strategy Pattern Let’s Look at some code Behavior defines interface
Context provide point for customization
Concrete implementations of interface
Decide who customizes behavior
Let’s Look at some code

29. 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)

30. Questions?

31. 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

32. 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.