3D Printing for Civil Engineers

3D Printer

3D Printer
3D printer
Lately I've been thinking our field might be missing out by not exploring the opportunities offered by 3D printing. Even though 3D printers have been around for many years, I haven't seen anything significant related to its use by agencies or firms in our field. I remember a 3D printer in use in a classroom at the college where I used to teach and that was at least 13 years ago. But that printer was used by the mechanical drafting students – not those in the civil technology field. So my partner and I have embarked on the goal of learning more about 3D printing and how the technology can be used in the civil engineering field.

Fortunately we found a learning program hosted by the University of Illinois in Champaign-Urbana which also happens to be our alma mater. The program is offered through Coursera and is a series of 5 courses leading to a specialization certificate in 3D printing. We began the first course right at the start of 2017 and are almost finished with the second one. So far the content has provided a good introduction to 3D printing and offered ideas about how it has been and could be used in many different fields.

Near the end of the second course, we were introduced to Josh Ajima, a teacher in Northern Virginia. In his presentation, he described how he created 3D representations of the earth's topography to visualize how different areas of a watershed relate. A description of his work with fabricating the Chesapeake Bay Watershed can be found in his article, "Design Challenge: Chesapeake Bay Watershed." Civil engineers can see right away how 3D printing an area's topography can lead to better understanding of watersheds, flooding impacts, material transport, and other related concepts.

Then, in our effort to learn more about the local 3D printing community, we attended a workshop at the Maker Lab in the Harold Washington Library in Chicago. There we saw a printout of the topography of the bottom of Lake Michigan. We were also introduced to the idea of using 3D printing to display data. An example of this type of use can be found on a 3D printing site called Thingiverse where the user anoved has uploaded a model of the United States to be used to visualize data sets for the states. A screenshot of anoved's Thingiverse page with the map is shown below. We can imagine an agency using this model for public education to show the amount of transportation funding spent by each state or the number of highway fatalities or miles of roadway.

Thingaverse Example of US 3D printed map with data

I'll continue to share our experiences with 3D printing as we learn more about the technology and increase our understanding of how it might fit into civil engineering. In the meantime, if you are interested in learning more, I'd encourage you to check out the classes on Coursera – they are free to take if you are not interested in earning a certificate for the specialization. You can also visit Maker Labs in your own areas – they are usually found in most larger cities, particularly in libraries. Also, if you know of any uses of 3D printing in our industry, we'd love to hear about them – just drop us an email, comment below, or reach out to us on social media.

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Using Augmented Reality to Visualize Engineering Designs

This week I experimented with using an augmented reality app at a public meeting to display this simple visualization of one of our projects.

3D model of a project using Augmented Reality

My experience was that it did seem to help with explaining or showing people not only an overall snapshot of how the roadway will look when finished, but it also helped show specific design and operational details that were difficult to describe. So I figured I'd post a quick explanation of the software I used to create the model and which app I used to host and display the visualization in case anyone else is interested in trying something similar out at their own meetings.

To begin, I would have liked to just export the project directly out of CAD and into the program where I assembled the 3D model because this allows for a more accurate representation and saves some steps. I've done this before using AutoCAD, and it was very straight forward and easy. Unfortunately we use Microstation at work instead of AutoCAD and so far I have been unable to find a way to get this to work with that software. The main problem seems to be that although it has 3D export capability, the program will not allow me to export something with a thickness so everything ends up flat. And it won't let me expand my export in the "Z" direction even if I import it into other 3D programs. I've spoken with a representative of the company, and as I've indicated in previous posts, he said Microstation is not interested in supporting this because they don't see a need for engineers to use this type of feature – as he put it "we're engineers, not gamers." So because of this, I had to create the 3D objects in other programs and use a PDF of the plan view as a guide in placing the objects. Also because of this and my time constraints I only modeled a portion of the project where there were no complex shapes.

So the program I used to create and assemble the 3D objects is Opensimulator. It's a free, open source program that runs as a web service and allows you to create and texture 3D objects then export them as models. You can set up Opensimulator on your own desktop by using something like SimonaStick or you can run it by installing it on your computer and connecting it to a service that allows you to access the interface with the use of a viewer. I used the second option and connected it to a service called OSGrid then used the Singularity viewer to log in and build. The main difference between building with this method and one that would use a more traditional 3D program like Blender is that building in Opensimulator is much more intuitive because you create using an avatar or 3D representation of yourself. Opensimulator has also greatly simplified the creation and texturing of objects.

Here is an "aerial view" of what my "build" looked like inside OSGrid right before I exported it as a 3D model.

As a side note, what is nice about building in Opensimulator is that you can use your avatar to walk through the project and get a feel for how it will function. If we were also building a streetscape, the use of an avatar helps assist in placement of elements. And from what I understand, if I had an Oculus Rift device, I could have put it on and immersed myself in the design as if I was actually there. This is something I hope to also eventually try as a design tool once I get a chance to buy one of those devices.

The only elements in the photo above that I could not create in Opensimulator were the cars and curbed medians. As you can see from the attribution note in the photo, the cars were 3D models I downloaded from the Kator Legaz website then uploaded into Opensimulator using Singularity. And I also uploaded a median that I created in Blender because I wanted the top to be curved like a regular curb is – Opensimulator does not allow for the creation of something like this so I had to use Blender then import the 3D model into Opensimulator. For all the graphics or textures applied to the models, I created them using a graphic software package then uploaded them into Opensimulator. There are many graphics programs that I use, but if you are looking for a good, free program, you can always use Gimp.

Once everything was assembled, I used the export 3D model feature in Singularity to create a Collada file of my build. Then I used my account on Augment to upload the model so I could access it and view it using the Augment app on my iPhone and iPad. Having the model available at the meeting made it convenient to show people what it will look like when built. For example, when I was having trouble explaining how the inlets impact the bike lane, I was able to just use this model to show someone how the inlets effectively reduce the bike lane from 7.5 feet in width to 5 feet if people do not want to ride over the inlet. Overall I would say having the model did enhance the ability to share our project with the community, and I hope to be able to build upon this experience to create more complex and detailed models in the future. If you want to check out the model yourself, you can access it here:

3D Model of Protected Bike Lane

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