Moving to Model-Based Design
Choosing Between 2D and 3D
Do you really have to choose between 2D and 3D? The answer is no, but it is important to know why. Over the past few years engineering design technology has begun an important transition: from automating traditional 2D drafting processes to developing 3D models as the basis of design. The building industry began this transition more than ten years ago, and today that industry is moving even further with building information modeling, or BIM. This transition has brought valuable benefits to the building industry, such as improved coordination of drawings, faster communication of design alternatives, and reduced field rework. Those gains can now be realized in the engineering and construction industries as well. It is not a question of 2D versus 3D; the methods need not be mutually exclusive, even in the context of a single project. For Civil engineering and construction professionals using 3D model based design software like Autodesk Civil 3D, you can get the benefit of both 2D and 3D.
To understand model-based design, you need to think beyond 3D. In model-based design, you create a data model of a proposed site development or road from which work products are generated: site volumetrics, road sections and profiles that are dynamically linked, parcel topologies, dynamic grading plans, conceptual what-if presentation models, design development drawings, and construction documents that might include plans, profiles, staking plans, details, reports, and presentation graphics.
Each deliverable is created from a central data representation of the site or road itself. By using model-based design methods, civil engineering professionals can create a more complete design model that includes important non-graphical data, 2D / 3D geometric data, as well as information regarding functional relationships, such as the association between a road and the right-of-way and abutting parcels.
Fig 1 Dynamic relationships of model-based design