What exactly does an Alignment do in Autodesk Civil 3D? That’s a loaded question. That may be the most mission critical question we can ask about the Alignment in Civil 3D. The familiar word – Alignment – is more sophisticated and nuanced in meaning these days. We certainly need to align our thinking with the Civil 3D functional realities.
If we have employed old-school, legacy CAD method and practice for a long time, we probably have some misconceptions about the Alignment Feature in Civil 3D. Autodesk invests a lot in their Alignment beasty. In Civil 3D, it pays to carefully consider the Do of the Alignment Feature carefully.
This post remains a work in progress. Significant updates and changes have been made to the original.
What can we do with an Alignment?
As I pointed out in the recent Alignment Types post, an Alignment isn’t what we see on the screen. That path of thought and talk often leads to confusion. The Alignment is all about the managed design control of the Alignment’s data behind.
The Alignment in Civil 3D is a collector - a managed bucket of data property buckets. Every named Alignment collects many other things. Maybe if we called the Feature something else that might help.
The Civil 3D Design Control Manager
This interpretation of the Civil 3D Alignment Feature name perhaps clarifies what the Alignment does better than the classic civil engineering word - alignment. Last post we talked about the Civil 3D Alignment Types. The Types are about the level of managed Design Control we need to do what we want to accomplish with a design or annotative process.
We might also consider the Alignment beasty is a collection of related data management interfaces. Civil 3D supplies these to the Civil 3D user through Layout toolbars, various Ribbons and panels, dialog boxes, and wizards.
Autodesk’s latest interface improvement– Project Explorer (PE) helps us better visualize and improve our overall understanding and the practical control of the Alignment, its children, and important relatives.
All these interface tools are hung together in patterns of usage. As Civil 3D users, it helps us to identify those patterns. Sadly, those patterns are beyond the scope of this post.
Kindly, Civil 3D is consistent in its interface approach given the complexity of the many related Managers listed here.
Shall we count the ways?
Horizontal Control Manager
This is what we classically think an alignment is in civil engineering speak. Hence Autodesk’s understandable misnomer. The Horizontal Control manager collects and manages:
- Site Parcel context
Intersecting Alignments in the same Site Parcel topology create Parcels – aka managed areas
The nuances of Alignment and segment direction isn’t quite as obvious as it first appears
- Reference Point
The X,Y location basis of the Alignment Stationing and related managed geometry
- Stationing and related Station Equations
- Design Speed
- HC Segment Type, geometry Constraints and Relationships, and the resolutions of the Segment math
We are responsible for Segment type and direction and how we approach the Alignment geometry definition by PI or Segment entity.
Design Rules and Criteria Control Manager
As we discovered last time this is what Alignment Type is there to manage.
- The applied HC Design Criteria Rules and Tables
- Design Criteria – customizable specific rules defined by Criteria Style
Vertical Control Manager
Profiles are hierarchical children of a parental Alignment. There is no such thing as a Profile without an Alignment in Civil CD.
- Site Parcel context and Direction derived from parent above
- VC Design Rules from parent above
- Design Criteria - customizable specific rules defined by Criteria Style
- Profile Views provide the graphic interface
We do not need Profile Views to have Profiles that make the design control function
- VC Segment Type, geometry Constraints and Relationships, and the resolutions of Segment math
We are responsible for segment type and direction and how we approach definition by PVI or Segment entity.
The PE interface is notably better at manifesting the Alignment to Profiles relationships and details. The PE interface provides quicker access to the standard Civil 3D design control interfaces.
Offset Control Manager
We could consider this Alignment-based set of services and tools to be the primary or secondary basis for Horizontal and Vertical Control to help us establish Cross Section control. This design by Offset approach is a bit non-intuitive from the historical civil design perspective.
How much we choose to employ either a primary or secondary role for Offsets depends on what we do in the downhill Corridor properties, the related Assembly Subassemblies’ properties, and perhaps some or all of the following:
- Offset Alignments and their Slope-controlled Profile children
Folks tend to love or hate these based on their experience level at managing them
- Choices of Corridor Baseline, Assembly, Region, Frequency, and Targets
Complex Corridor - Multiple Baseline Corridor – designs are often dependent on the Offset Control Manager functionality inherent in related child Offset Alignments and their Slope controlled Profiles.
See the Site Grading with Corridors page, posts, and videos for some examples.
Site Parcel Manager
We already mentioned above that the Alignment Horizontal, Vertical, and Offset Control Manager functionality can be applied constructively to help us better manage many civil engineering design process Civil 3D Site Parcel topologies.
Can shared project-based DREF Alignments and their managed Offset children be employed to develop appropriate Site Parcel and Parcel collections? Of course.
Alignment Site Parcel Manager functionality extends beyond common easement and right of way design conditions to other important and Alignment related design development challenges that involve dynamic area resolution issues.
Superelevation Control Manager
The Superelevation Wizard attempts to resolve and compensate some, but not all, of the above and produce Horizontal and Vertical Control adjustments to the roadway Design control based on several supported methods and design norms.
- Superelevation Views, Band Styles, and Tabular Editor provide display and edit interfaces
- Assemblies, Subassemblies and PKT files can deliver the tools to manifest the superelevated slope control
Manual Superelevation edits performed inside the Tabular Editor provide us methods to apply cross section slope control to station ranges of both tangents and curve segments alike.
The nuance of managed tangent slope control capability can be important in the design of roadway intersections for example. There are other appropriate design applications for manual superelevation design control on tangent segments in an Alignment.
The Corridor Engine Manager
The Civil 3D Corridor engine functionality is dependent upon Alignment and Profile pair Baselines. Corridor Feature Line based Baselines, available in more recent versions of Civil 3D, cheat and construct hidden Alignment and Profile pairs behind the scenes.
Most of the Civil 3D Alignments we construct in a Civil 3D project will sooner or later build or be related to a design Corridor or Corridor output results.
Corridors produce Feature Line output which in turn will produce new Alignment and Profile pairs via one or more forms of output or conversion.
Feature Line Manager
Corridors produce Code managed Feature Line output from DREF shared Corridors. That project-based Feature Line data will in turn will produce new Alignment and Profile pairs via one or more forms of output or conversion.
It seems obvious that managed collections of shared Feature Lines are a more productive design approach than individual Feature Lines in individual design drawings.
Pipe and Pressure Pipes Manager
These days all the current forms of Pipe Network systems in Civil 3D include Alignment-based design and control mechanisms and dependencies. The Civil 3D workflows for these network systems are actually more Alignment (or Run) based than they are network system based.
How responsive our design is to changes is directly related to how, when, and where we skillfully employ the many Alignment design control managers and tools already mentioned above and discussed below.
The creation, edits, and maintenance of Shared Alignment-based project Data References quickly becomes a significant production issue in Civil 3D pipe design.
The Alignment - Design Control Manager - is employed by Civil 3D users to develop, manage, and maintain all that work.
The Alignment's Design Control Manager capabilities extend to project publication as well.
Plan Production Tool Manager
Sample Line Groups, Sections, and Pages of Sections are obvious Toolspace children of parent Alignments.
ViewFrame Groups are separated in the Civil 3D Toolspace interface, but ViewFrame Groups are themselves always related to a parent Alignment at birth.
All the automated Civil 3D Plan Production Tools are Alignment centric and dependent on named Alignment references in one fashion or another.
This Civil 3D production reality is much more apparent and much more significant in the shared Project-based context (Data Referenced (DREF) data) than in the individual working drawing context. Best to always keep that DREF project-based reality in mind. It is easy to forget in the heat of the moment.
See the Flexible Civil 3D Corridor Labels post and videos.
Inside Civil 3D, unless we really want to avoid automated publication of our deliverables all together, Alignments become a centerpiece of production output deliverables production.
The Alignment is An Annotation Manager
What we want to display in Civil 3D at the moment often makes all the difference. The current State of a Managed Dynamic Model is always important. It is safe to say that State sometimes frustrates us in Autodesk Civil 3D. Put another way - Life without the appropriate Style choices can be hell.
The Frameworks for Civil 3D can fix that.
All the many other Design Control Managers here can make us lose sight of the fact that Alignments and the many potential children have lots of potentially different forms of Style and other inherent capabilities like Masking. Style can make Alignment Features invisible. Marking can make parts of an Alignment invisible by Station Ranges.
Alignment Style collections include Civil 3D’s largest collections of Label Styles and potential Label Sets and members.
Simply put - Group Labels Rock.
Rock and Roll with Group Label Style
You can make the linework for Alignments and Profiles look like almost anything with the simple combinations of the linework Style and applied Major and/or Minor Group labels. Yes. That Label Style capability may include symbols. One may argue that we can almost dispense with linetypes in Civil 3D provided we are willing to support the Style collections and learn to employ the annotative Alignment manager well.
We’ve talked about Annotative Alignments often enough before. We won’t belabor that here. Our Framework for Civil 3D products and most notably Jump Kit include many of these Style tools.
Do we Manage our project-based Annotation with Alignments?
All these separate and interlaced Alignment Design Control Manager functions beg the serious question,
“How do we name and share this Alignment?”
Name, Share, and project Structure are wound together around the Alignment in Civil 3D.
The Liberty to Make Civil 3D Work
Get the Framework for Civil 3D Release 8
The Book of Alignments Posts
A study guide to Read and Test in Civil 3D
Updates to this post series are on-going.