3D Modeling: Embracing the Technological Gains, Examining the Professional Impact

By Ronald E. Gant, P.E. Global Civil Marketing Director, Bentley Systems

I have recently been privileged to attend numerous presentations by colleagues, competitors, customers, and civil software users and have found 3D modeling to be a major topic of interest. 3D modeling is often mistakenly perceived as a new concept to civil engineering; however, this is not the case. 3D modeling has been in use for many years, though it appears that civil engineering has not taken advantage of this capability as much as our manufacturing, mechanical, and architectural colleagues.

3D Modeling Is Not New
Product developers at Bentley made 3D modeling available back in the mid-1980s, and coincidentally, Bentley will be celebrating 20 years of 3D modeling later this year. No doubt, 3D modeling has matured and evolved over time. Our initial concept of 3D modeling was based on the ability to model the ground as a 3D surface — no depth, no particular objects, no features or intelligence — simply a 3D model of the ground as it existed.

For over 10 years, this 3D model of the earth was sufficient. In the mid-1990s, however, a number of vendors, with Bentley as a major proponent, realized that our civil industry required more than a simplistic ground surface. Civil engineers and software developers recognized the need to incorporate intelligent features and objects, such as underground piping and structures, geotechnical strata, and other project salient features into their 3D models. So began the initiative to create a more inclusive 3D model comprised of these objects and their attribution, both above and below ground level.

3D Continues to Evolve
By the early 2000s, designers could model a highway or transmission corridor and display bridges, overpasses, signage, and even transmission lines – measuring clearances, swag, and sway. Civil engineers could intelligently identify, relate, annotate, and label objects within their designs. These capabilities continued to evolve, but were oftentimes hindered by hardware and digital memory limitations.

As our hardware and operating systems became more powerful, software developers could take advantage of emerging technologies to develop more sophisticated civil engineering tools. Unfortunately, the civil industry did not readily embrace the available potential for robust 3D modeling, and software companies developed to industry expectations.

In retrospect, the civil industry was taking great pains to protect and safeguard the equity that civil engineers had invested in their expertise, methodologies, and training – all that is necessary to produce a solid design as well as the deliverables required for construction. Civil engineers continued to do much of their work based upon plan views tied to profiles and cross sections, looking at the world from a kind of 2½D perspective.

Though 3D modeling was in use and effective, civil engineers very carefully and pragmatically continued to model in a manner which allowed them to design in a 2D/3D environment — maintaining time-honored traditional workflows to produce established deliverables. Likewise, civil contractors continued to construct using conventional methods.

21st Century Construction
The civil engineering profession and construction industry are engaged in another technology evolution. Acceptance of 3D technologies for GPS and the use of GPS for machine guidance are becoming more widespread, enabling constructors to better maneuver and locate equipment along strings or alignments. Today construction equipment operators can control the pitch and yaw of blades from a model existing on the equipment and incorporate many of the geospatial characteristics that have become so commonplace within the civil environment.
Construction has moved into a true 3D operating mode with the ability to very precisely carve slices of earth to create roadways, building pads, and plant earthworks and foundations — all automated through machine guidance or machine control. As in the late 1980s and early 1990s when 3D modeling drove the concept of generating DTMs and 3D earthworks, the civil engineering design industry is now compelled to produce complete, accurate 3D models that can be uploaded to equipment for contractor use with evolving tools for machine control and machine guidance.

These exciting advances in high level 3D modeling and machine control and guidance spawn very interesting challenges for civil engineers as well as the civil industry at large:
1. How do we retain the value of the engineer’s experience in completing a design?
2. How do we avoid radically changing the engineer’s workflow so that we do not have to retrain all our engineers?
3. How do we keep engineers in control of evolving, changing design processes so that they fully understand the reason, cause, and effect of changes being made?

Any solution that makes civil engineering decisions without allowing engineers to stay in power and use their well-founded decision making capabilities is simply a black box.  Highly automated 3D modeling does not have to come at the expense of traditional design creation and proven well-crafted, well-developed methodologies.

Creating a good design that can be built at a good value involves infinite intangibles, and technology has not so evolved that it can program in all the expertise and decision making skills of a trained, experienced engineer into a piece of software. While software can be made to react faster than humans, unless we as engineers understand every decision being made by programmatic software, we are putting our trust in a “black box”, not the engineer.

It is very important that engineers be able to visualize updates as they occur in their 3D models, to fully comprehend how and why any design changes occur as well as understand the effects thereof. While I have seen recent efforts promoting the “black box approach”, I feel that the civil industry must carefully consider how such a mindset not only radically affects trusted, proven workflows and methodologies, but impacts civil engineering as a profession.

Moving Forward While Protecting the Legacy
When first entering the civil industry as a young engineer, I worked with astute, trusted engineers who truly “knew” their designs. They had a tremendous capacity to look at their design and “know” whether it was right or wrong. They had the skill and knowledge to make necessary corrections and resolve inconsistencies. They had the ability to lead and communicate, through their heightened expertise, how to create better designs. They fully comprehended “the big picture” of civil construction and appreciated how and why they used specific methodologies and practices.

We must exercise caution as we move forward, technologically speaking, to ensure that “black box methodologies” do not diminish the value that learned, respected engineers bring to our civil engineering world, that they retain their ability to pass true knowledge on to the young engineers who will be designing, creating, and maintaining the civil infrastructure for years to come. When we look at evolving design practices, we must not relinquish traditional methodologies. Rather, it makes good sense to enhance traditional methodologies while still providing younger engineers the capability to see their designs as they are formulated. Let’s delve more into dynamic modeling, multiple view design capabilities, the ability to stop and pause movement at any time in the design process, and how to better evaluate the decisions that the software may make for us to be certain that the software is doing what we, as engineers, need it to do.

We must keep in mind that software does not put a stamp on a drawing. Only qualified, proven engineers do that. So, let’s take a step back to consider 3D modeling from an overall perspective. Yes, we most certainly want to take advantage of 3D modeling capabilities, but let’s do it in a fashion that allows us to view changes, to see the impact of those changes, and see exactly what is occurring throughout the modeling and design process. Let’s provide the ability to view a design as we move through it, to view movement along the design, and to be able to QA that design.

When we provide our finished deliverable to a contractor, we must “know” that we are providing something that is technically sound and correct. We must be certain that it can be built as designed, that the piece of equipment that is forming the 3D model of the ground has the ability to follow the design specifications so that what is created is what the engineer put in the drawings.

Sustaining Our Profession and Infrastructure
We cannot and must never forget that we are producing civil engineering drawings that shape our environment. Our drawings are the tell-tale design standard of what we are doing to our models, to our earth, and more long term, to our infrastructure that must be maintained for the safety and well-being of generations to come.  We welcome 3D modeling as the wave of the future, but experience, wisdom, and personal accountability dictate that we ensure design integrity. Oftentimes we look for the easiest way to complete a process; however, that can mean a loss of control. Personally, I rest better at night when I know that cutting edge technology is in the hands of experienced, respected civil engineers who confidently lay their reputations on the line and are willing to sign off on the designs that affect me, my family, and my community.