Two Powerful Updates to Corridors in Civil 3D 2017

While teaching a Civil 3D 2016 class one of my students asked “Can you create a corridor from a feature line?” At the time, the answer was “No, you can’t.” In order to create corridors in Civil 3D 2016 and earlier releases, an Alignment and Profile were required for the horizontal and vertical geometry information. In Civil 3D 2017, the answer is absolutely “Yes, you can," no Alignment or Profiles required. If your feature line has elevation data you get a corridor from that. Yes! And not only can you create a corridor from a feature line, you can also share it across the project team by creating a data shortcut. 

If you have been waiting on the sidelines, wait no more – these two productive corridor updates are enough to justify upgrading to Civil 3D 2017.

With the ability to create data shortcuts for corridors and use them in multiple drawings you can split a huge corridor into multiple drawings and get a performance boost, resulting in a huge time saver; you can create a corridor in one drawing and use it in another.

This does change the workflow of creating cross sections from a corridor. Prior to this, you had to XRef the corridor drawing – that lead to a performance lag because you ended up working with the whole drawing even though you just needed a corridor. With this shortcut you load only the corridor, which is huge in terms of productivity gains.

The pre-2017 workflow would be to create an Alignment and then a Profile view. You had to make sure the Profile view displayed the right elevation so you could create a layout Profile, and only then would you be able to create the corridor (assuming you did not create an existing surface Profile).

The 2017 process doesn’t replace Alignments or Profiles because you cannot create data shortcuts for a feature line, yet. But this new method does gives you an option other than projection grading, aka grading object. Meaning, this will work great for parking lot grading, which has many feature lines for which creating an Alignment and Profile for each feature line is too time consuming and impractical.

So, create a corridor from a feature line and share it using data shortcuts – two powerful corridor updates that save a ton of time and easily justify upgrading to Civil 3D 2017.

Watch this video to get started!

Don’t forget to look through other great features our Ideate Technical Team has found in the new 2017 releases for Civil 3D, Navisworks, Revit Architecture, AutoCAD (and more) on our Ideate Solution Blog.

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Guarav Bagga

Senior Application Specialist Infrastructure 

Gaurav is a Senior Application Specialist for Infrastructure Solutions at Ideate based out of San Francisco. He has over 18 years of experience in construction and related software industry. With this extensive design technology background he helps engineering and surveying companies, federal and state government agencies, and ENR 500 firms critically analyze and improve their construction drawing production process. He implements Civil infrastructure design technology led by InfraWorks and Civil 3D and has helped Ideate grow Civil Infrastructure Services. Being an industry recognized speaker he has presented cutting edge design technology at several industry conferences such as Autodesk University. Find Gaurav on Twitter.

US Survey Feet is Finally Here

As a Civil Engineer and Infrastructure Application Specialist at Ideate, I'm celebrating along with Surveyors, Mappers, and Civil Engineers in nine states… AutoCAD 2017 based products now support US Survey Feet! 

It's been something we've wanted for years because many of us assign our drawings a State Plane Coordinate System (SPCS) using AutoCAD Map 3D or AutoCAD Civil 3D. US Survey Feet is preferred by California, Texas, Colorado, Connecticut, Maryland, Indiana, North Carolina, Nebraska, and Wyoming. The issue up until now, was that although Map 3D and Civil 3D functionality understood coordinate systems, and the difference between a US Survey Foot and an International Foot, underlying AutoCAD did not. AutoCAD tools to attach External References, insert blocks, and ReCap point clouds, auto-scale based on International Feet. The difference between a US Survey Foot (~0.3048006 meters) and an International Foot (0.3048 meters exactly) is quite small. Yet it makes a significant difference when you are working in large state plane coordinate values for mapping and civil engineering projects.

Now the sobering news… because 'US Survey Feet' is a new unit to AutoCAD (INSUNITS=21), potentially undesired automatic scaling of Xrefs will occur if we are not careful. Why do I say that?

Externally referencing a ‘legacy’ engineering drawing (pre 2017), set to Intl Feet, into a 2017 'US Survey Feet' units drawing will now be automatically scaled, regardless of whether the application performing the reference is AutoCAD 2017, Map 3D 2017 or Civil 3D 2017. This will also occur even if the referenced drawing is assigned a coordinate system based on US Survey Feet. Remember that attaching an Xref is an AutoCAD based tool. The auto-scaling will not be obvious in the Attach External Reference dialog because the default Drawing Units length precision in most drawings is set to four decimal places.

Now, if you set your Drawing Units length precision to six decimal places, you'll see a scaling factor of 0.999998.

This is the ratio of Intl Feet to US Survey Feet, which comes to about 2 feet for every 1 million feet. It's negligible for low coordinate value drawings, but not for our state plane coordinate drawings. 

In the below screen shot, I've externally referenced an Intl Foot drawing into a new 'US Survey Feet' drawing. Note that the coordinates of the same point differ by -12.51, -4.07. 

Also note that 'US Survey Feet' is not understood by AutoCAD versions prior to 2017. You'll get the below warning upon changing the units. An AutoCAD 2017 created drawing can still be opened by AutoCAD 2013-2016.

Lastly, some of you may be aware of an old undocumented AEC command called -DWGUNITS. It's occasionally used to address block insertion scaling of 12x or 1/12 even when INSUNITS is correct in both drawings. Because it's old and undocumented, it does not include US Survey Feet.

Although it's great news that Autodesk finally added US Survey Feet to AutoCAD's supported units, we may not fully realize the benefit for a few more releases. Until then, I recommend setting the Drawing Units length precision to six decimal places for all drawings assigned US Survey Feet. Doing so will give you the visual prompt of the auto-scaling AutoCAD is about to perform.

For more information on training and consulting for the various products Ideate services, visit our website at www.ideateinc.com

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Daniel Armstrong
ENI Application Specialist
Daniel is an Application Specialist for Infrastructure Solutions at the Ideate Sacramento office. He is a California licensed Civil Engineer and LSIT with over 9 years land development design experience and 6 years Civil–GIS software consulting. Additionally, he provided 6 years of engineering support at a municipal public works department. At Ideate, Daniel assists Civil Engineering and Surveying firms in maximizing their utilization of AutoCAD Civil 3D through consulting, training, mentoring, and technical support. He conducts standard classroom and custom training on AutoCAD, Map 3D, and Civil 3D.