Last week, on, Dmitry Ushakov published an article titled Direct Modeling – Who and Why Needs It? A Review of Competitive Technologies. If you’re interested in CAD productivity, I recommend reading it.

The article includes one of the most cogent explanations of direct modeling I’ve seen. It also includes a thoughtful discussion of the drawbacks of history-based parameterization—the method used by mainstream CAD programs such as Pro/E (Creo Parametric), SolidWorks, and Inventor.

One of the small gems in the article is a reference to a 1995 article in HP’s corporate journal on SolidDesigner (which became CoCreate, and more recently Creo Direct.)

There’s a small footnote in the HP article mentioning “3D/Eye of Ithaca, New York and D-cubed of Cambridge, UK.”

That caught my interest. A quick Google search, and I found a note in a 1996 issue of Ralph Grabowski’s upFront.eZine, which quoted a reader as saying “3D-Eye wrote much of Solid Designer under contract to HP… They wrote the graphics, some of the UI, and a lot of ACIS husks to work around the limitations of the modeler.”

3D/Eye also wrote Trispectives, which was the predecessor to IronCAD. In 1997, the core development group at 3D/Eye was acquired by Autodesk.

It’s interesting to look back, and see where things came from.  Direct modeling is a big deal today — but its roots go back a long way.