This is an article written by John Groener of Edge Data.  He is a reseller of both AutoDesk and Kubotek CAD software.  I hope you enjoy his perspective and find it informative and educational.  His contact information follows.

Direct
Versus History-Based Modeling

In 1985 History-Based Modeling was implemented in Pro/Engineer® and quickly
imitated by several “Me-Too” CAD products such as CATIA®, SDRC IDEAS®, and
UniGraphics®. Then came the “Mini-Me-Toos” such as SolidEdge®, SolidWorks®,
IronCAD®, and Inventor®.

History-Based modelers require the CAD user to define parameters and
constraints when designing a part. The parameters provide relationships to
other features in the 3D part, and constraints allow that part to be
constructed unambigously.These parameters, features, and constraints are stored
in the order they were built in the history tree and must be accessed through
that tree to be changed.

History-Based Modelers have shortcomings.
 •    Engineering changes can be a difficult, painful
process. A new user has to decipher and untangle the history tree so that he
can make changes.
 •    Each CAD software package has its own proprietary
file format so parts are not easily interchangeable.
 •    Assemblies can be time consuming to set up and
manipulate.
•    There is no stand-alone 2D drawing capability.
•    Surface models are not easily interchanged with solids.

KeyCreator uses Direct Modeling to create and edit 3D Models. NO
user-defined history tree is needed. Why? Because KeyCreator creates the
feature tree and KeyCreator allows direct dimension driven editing.  In
other words parametric, feature-based editing of all geometry.

KeyCreator has Comprehensive 2D drafting. KeyCreator produces complete
2D drawing sheets associated to the 3D model. KeyCreator uses levels (aka
layers) to manage 2D information, so 2D drafting can be standaone if desired.

KeyCreator Reads Native CAD Files from other CAD software like Pro/E,
Solidworks, Unigraphics, CATIA, Parasolids, ACIS, STEP, IGES. No fixing, no
healing, just read it in, edit, and GO!   Wait … how about the
parametrics? That’s KeyCreator’s job. No need to use the import as reference
geometry and re-parameterize it. Just go to work.

KeyCreator incorporates surface modeling. With KeyCreator you can create
a free-form surface model and then convert it to a solid model to facilitate
operations like shelling and fillets. Excellent healing tools insure that the
part is completely contiguous and accurate. KeyCreator is therefore a TRUE
Hybrid Modeler (a hybrid of solid and surface models).

KeyCreator’s assembly modeling features can manage all data in a single
file. It does this by using level management – that same invaluable 2D tool
which is noticeably absent in the other Solid Modelers. For very large
assemblies, KeyCreator can export parts in the assembly to multiple part files
and then reference those parts as entities.

KeyCreator is a complete Mechanical CAD solution with a unique ability to read
any CAD data format and then easily manipulate geometry, making it an
invaluable resource for any engineering design and manufacturing application.

KeyCreator and Edge Data

Did you know that …
… KeyCreator®, formerly known as CADKey®,  was introduced in 1984 as a CAD
Package with 3D Digitizing capabilities.

… Kubotek Corporation purchased CADKey in 2003, renamed the software
KeyCreator, invested heavily in R&D, added advanced 3D, CAM, and universal
CAD translation.

… Edge Data, one of the first AutoCAD dealers in the country, has been
providing New England with CAD products and training since 1983
…Today Edge Data is an Authorized Kubotek Service Center, and provides CAD
training for KeyCreator and other software.

John Groener
Edge Data Corp.
authorized kubotek service center

www.edgedata.com

978-537-9800
john@edgedata.com

Source: CAD Freedom and Precision – Views and News from KubotekUSA – Direct Versus History Based Modeling
Go to Source: CAD Freedom and Precision – Views and News from KubotekUSA