Explicit modeling

With the explicit modeling, designers quickly and easily create 3D CAD designs, which they then modify through direct, on-the-fly interactions with the model geometry.

Advantages

The explicit approach is flexible and easy to use, so it’s ideal for companies that create one-off or highly customized products –products that simply don’t require all the extra effort of up-front planning and the embedding of information within models. With an explicit approach to 3D design, the interaction is with the model geometry and not with an intricate sequence of design features. That makes initial training on the software easier. But it also means designers working with an explicit 3D CAD system can easily pick up a design where others left off–much like anyone can open up and immediately continue working on a Microsoft Word document. Thus explicit modeling appeals to a variety of audiences: companies with flexible staff, infrequent users of 3D CAD, and anyone who is concurrently involved in a large number of design projects.

Use in repurposing

When designers repurpose a model, they take an existing 3D CAD design and radically transform it by cutting/copying/pasting geometry to derive a new model that has no relationship to the original model. With an explicit approach, companies have demonstrated accelerated product development by repurposing existing designs into new and completely different products. This unique characteristic of an explicit approach can shave weeks or even months from project schedules.

Even with direct modeling capabilities, the parametric approach is still designed to leverage embedded product information. The explicit approach, on the other hand, intentionally limits the amount of information captured as part of the model definition in order to provide a genuinely lightweight and flexible product design process.

Parametric vs. explicit approach

With a parametric approach, data files include parameters, dimensions, features, and relationships that capture intended behavior. An explicit approach, however, reduces data files to the 3D geometry only, dramatically reducing the design data of each individual part, so large and complex designs don’t overwhelm hardware or software. Smaller file sizes mean designers can load and store data files faster, reload and update parts to new revisions instantly, and make better overall use of their computer memory.

Use in data management

When combined with a data management system, an explicit 3D CAD system can also help manage complex relationships associated with large assemblies. For example, an integrated data management system automates revisioning and encourages true concurrent team design because all designers have access to the most up-to-date design data. When all design data is centralized in a common database, companies can ensure that no one works on the wrong revision of a component, or changes a component reserved by someone else.

Explicit 3D CAD systems excel at importing and modifying of multisource CAD data, which benefits companies working across an extended supply chain for procured components or subcontracted design. STEP and IGES are essentially native 3D design data formats in an explicit approach because explicit 3D CAD systems interact intelligently and on-the-fly with geometry, and geometry is the only common element across all CAD systems. The explicit approach to 3D design, with its lower overhead and flexibility, offers a better solution, especially for companies that rely on the ability to radically adapt and change to new and shifting design requirements.

Use in product development

Companies that develop new-to-market and one-off product designs often face changing customer and product requirements throughout the development cycle. An explicit approach is always open to change, so companies can keep the window for new product information and major product changes open longer. Unlike other 3D design approaches, including hybrids, explicit modeling can offer true flexibility because it doesn’t require any upfront planning or the embedding of design information within models.