Engineering by definition is a rather straightforward pursuit. Using scientific and mathematical principles to solve problems sounds pretty rigid, right? The reality of problem solving, however, is that it is inherently a fluid process, one that continues to flow and evolve until an optimal solution is found.
In product design, this means exploring, iterating, changing, testing, and changing again until an optimized product is conceived, design and build. And, designing a truly optimized product means trying different things until you fail. After all, until something—an ideal, a prototype, or a model—fails, it’s nearly impossible to optimize it.
As a result of the optimization process, CAD software must also be flexible, enabling CAD models to absorb and respond to change without significant effort or the user having to recreate the model from scratch. Though advancements in CAD software have greatly improved the ability to design products faster and perhaps with less mouse clicks, making design changes remains a challenge, especially when dealing with CAD models created by others.
Do current CAD tools inhibit modeling flexibility?
Parametric modeling provides engineers with a methodical, orderly and powerfully automated way to create models. Feature-based modeling tools also require engineers to anticipate and define feature constraints, relations and dependencies, which ensures that any design change will update all related downstream geometry.
History-based modeling provides users with a more powerful and automated way to create complex models, especially for large assemblies that use families of parts. These systems are ideal when designers are held to strict criteria, such as specific design aesthetics, performance metrics, and manufacturing criteria.
The downside comes into play when other design participants must make changes to these models. When these parametric models are imported, there is no mechanism to initiate changes, so users must remove and recreate different pieces of the geometry that they need to change through parameters and features.
Direct modeling tools facilitate multi-CAD collaboration, design reuse
Another modeling paradigm, direct modeling, enables users to take a more flexible approach to creating geometry. Because direct modeling CAD systems don’t have the overhead of history-based systems, users can directly manipulate model geometry without regard to how that geometrPost ony was created.
The main advantage of direct modeling systems seems to be ease of use along with a significantly shorter learning curve, which opens up CAD to non-specialists who are now integral members of the design review team. Users simply grab, pull, and drag geometry to edit or make changes. By deploying the use of direct modeling tools, organizations can foster greater innovation and fuel product concept pipelines with the help of those outside of the engineering department.
By providing a common CAD platform, direct modeling systems also make dealing with CAD data in multiple formats easier. This is a big benefit to most companies with multi-CAD environments who must juggle CAD data from partners and suppliers that was created in various CAD systems.
Reuse of existing designs without unnecessary rework is also more easily accomplished using direct modeling tools since importing design data from any source is easier. Designers can leverage all types of available content—such as sketches, surfaces, single parts, or entire assemblies—without data interoperability problems since STEP and IGES are viewed as native CAD data to direct modeling.
Having the best of both worlds
Both modeling approaches have their pros and cons, which is why PTC has introduced a solution that makes it possible to use the best of both. PTC Creo Flexible Modeling Extension (FMX) allows users to edit geometry regardless of whether it is independent or constrained while providing multiple selection criteria to quickly handpick the desired geometry for editing.
The functionality offered in PTC Creo FMX is ideal for designers and engineers who need to work with designs created by others using different CAD systems. These engineers need the capability to make quick changes without having to override the design intent. PTC Creo FMX also gives users the option to go back later when they have more time to formally revise that design intent, as needed.
See how you can use the right tool for the right job now by giving PTC Creo a free 30-day test drive by downloading it here.
