Issue: Volume: 24 Issue: 2 (Feb 2001)

FreeForm Gets NURBS

FreeForm has been used to create models for the film and entertainment industry, and also to design toys, electronics, furniture, and other products, but previous versions confined users to working with one block of digital "clay" at a time. The new multipart functionality lets users create models in pieces. Now a designer can, for example, model the legs of a doll separately from the body, with the option of combining or re-separating the elements on the same screen. Other new modeling tools include lofting and wire cutting, which allow product designers to quickly produce compound curves based on sketch profiles, and the ability to create textures and patterns directly on models.

Previous versions of FreeForm output to STL and OBJ file formats, but Version 3.0's ability to output to IGES surfaces as well adds NURBS to the mix. Once a model is created, a user can define NURBS patches by placing curves directly on it, and the model can be output straight to a NURBS modeling package. Other production-related improvements include parting line evaluation, which allows modelers to identify potential undercuts in models early in the design cycle, and a new paint capability that lets users paint directly on finished models.

"The big thing in Version 3 that I like is the surfacing," says Muggs Ferguson, director of new technology for R.J. Studios, a prototyping house in New town, Pennsylvania. Ferguson says he uses FreeForm both to sculpt models (mostly toys) from scratch, or to reverse engineer them from scans. Because the CAD package his company uses is not adept at handling complex organic forms, the surfacing in the new version comes in handy for the shelling of models before they are imported into CAD.

FreeForm 3.0 runs on NT/2000 operating systems with an approved OpenGL graphics card and a recommended 1gb of RAM. Though SensAble also recommends dual 400mhz processors (the application is multithreaded, with one processor handling the haptic device and the other the software), Version 3.0 can run on a machine with a single 800mhz processor. The FreeForm system costs $25,000. (SensAble Technologies; -JD