Finding New Paths to Move from 2D to 3D, 1 in a Series

By DE Editors

For more than 20 years, the design and engineering world has been extolling the virtues of moving from 2D to 3D. Yet, while 3D solid modeling delivers precise models that designers can accurately visualize, analyze, and manufacture, 2D continues to flourish. Regardless of 3D’s strengths, 2D is still critical in the conceptual and design processes of many manufacturers.

Why is 2D still so popular? The reason is simple: 2D provides a hands-on environment focused on getting the job done. In traditional, feature-based 3D systems, designers and engineers must work with dedicated 3D CAD experts to build a recipe for their designs. Solving the actual design problem often falls second to weighing the tradeoffs of their feature architecture. To use a feature modeler effectively, designers must learn how to manage dependency structures and fix rebuild errors when they make changes that conflict with assumptions in the existing feature architecture. Although feature modelers are powerful, the overhead they add to the design process can outweigh their benefits.

Many design opportunities—such as large machine layouts, floor plans, and rotationally symmetric equipment—are fundamentally 2D, demand a 2D environment, and are most conveniently solved in 2D. A simple part like a wave spring can be represented in 2D with a few picks while modeling it in 3D can take hours. Even looking at a 3D design is more complicated than viewing a 2D drawing: external parts obscure interior parts, so designers must constantly show and hide components and rotate the model to understand what’s going on. 2D sections often best explain designs with significant internal detail. In traditional feature modelers, however, 2D can only be used for documentation.

New 3D design tools are bridging the gap between 2D and 3D, however, creating viable new paths—each with advantages and disadvantages. Feature modelers, for one, are well-suited for highly configured, knowledge-based engineering and applications where families of the same model must be generated repeatedly. But feature modelers must be carefully deployed and implemented because they are complex. To be effective with a feature modeler, users must fully understand the design they are creating before even beginning the design process. If designers don’t properly build feature-based models, maintaining the models becomes challenging. Companies implementing feature modelers should commit to one CAD system and standardize throughout the user base and supply chain because models created in one feature-based system are not reusable in another.

3D productivity tools also create accurate solid models and drawings and enable designers to focus on the design rather than the recipe, just like most 2D systems. They are well-suited for conceptual design, one-of-a-kind and customized designs, and situations where existing 3D models must be edited, de-featured, or reused in new ways. They can be used with existing 2D and 3D systems, so existing tools don’t have to be discarded. And they let designers create and edit drawings directly so they can focus on getting work done, not creating abstract product models.

This emerging technology provides a more hands-on environment. Don’t expect to create complex models with inter-component relationships where editing a few dimensions can drive changes across thousands of components. Instead, make edits by selecting what needs to change and manipulating the model directly. 3D productivity tools are not a substitute for 3D processes, and dedicated CAD users might prefer feature-based environments.

Until recently, 2D may have been the best tool for many designers and manufacturers, but users who have found that feature modeling didn’t suit their process might find that emerging 3D productivity tools offer an attractive approach to solid modeling.

Blake Courter co-founded SpaceClaim Corporation in 2005. He has been in the 3D design industry since receiving a B.S. in mechanical engineering from Princeton in 1996. Please send your comments regarding this commentary to [email protected].