This blog is posted from German with DeepL.
Depending on which side you come from, you miss one or the other! As a rule, one knows the parameterized development tools from the basic training – so-called “feature based modeling”. This starting position often leads to first obstacles with non-parameterized systems (direct modeling). In the end, one mainly misses the history. The common CAD systems are based on this approach. Each machining step is listed chronologically in the history and depends, directly or indirectly, on the feature before it. Does this still meet today’s requirements?
“Direct Modeling” takes a different approach: “Geometry is KING”. The designer can interact directly with the model and model it like a piece of clay in the true sense of the word. In addition to the usual means used in other CAD systems, such as sketches, extrusions, drilling, chamfers, curves, etc., a surface can also be dragged, compressed and rotated using “drag & drop” and other functions.
This freedom changes the way parts and assemblies are developed and allows a very flexible and fast creation and customization of CAD data.
Especially for concept work, this enables the implementation of large and small changes with very little effort. The clean setup and planning of a part is completely eliminated. In addition, data preparation for simulations is very efficient and flexible.
Another advantage worth mentioning is the compatibility. Common 3D formats such as STEP and IGES can be exchanged independently of the direct modeling software and the version.
Of course, Direct Modeling also has its limitations. Complex assemblies can be problematic. Likewise, the missing parametry is a disadvantage if, for example, assemblies or parts are to be controlled (dependencies, tool adjustments, scaling, changes to complex geometries, etc.).
Many well-known suppliers have already integrated direct modeling functions into their systems or are working on it. We think that direct modeling can only complement classical parametric modeling in the foreseeable future and not replace it in all areas. Systems that combine both approaches in one will possibly be able to fully establish themselves in the future.
We experience the PTC Creo Element/ Direct software as intuitive and easy to learn.
PTC even provides an older version (6.0) of the system for free. It is fully functional except for some limitations. Tobias Theuer uses this software, among other things, to design his STANDFEST furniture.
Direct Modeling (Creo Elements/Direct)
Move surfaces, geometries or components with a few mouse clicks.