White paper 'Variational Direct Modeling: How to Keep Design Intent in History-Free CAD'
What is better: history-based modeling or direct modeling for 3D design and editing? Both approaches have their advantages and their drawbacks. Can smart parametric editing be be combined with simplicity of user's manipulations? The answer is in the new technology - variational direct modeling: using geometric and dimensional constraints to define the desired model behavior when modifying the model. A variational direct modeler simultaneously satisfies all constraints in contrast to the history-based consequence in parametric modeling. The set of constraints is a declarative construction to be interpreted uniformly regardless of their history. At the same time, constraints expressivities are sufficient to specify features and links between them. Constrains are set not only by a system user but also by the system itself which automatically identifies them building the original model or importing the model from another system. As a result, there is an easy-to-use tool to control feature concept of a product, which can adequately replace the current history-based and direct geometric modeling systems, combining their pluses and concealing their minuses. This paper describes advantages of variational direct modeling applications for the end-users.