Issue: Volume: 23 Issue: 1 (January 2000)

Reviews: FreeForm

In the film and commercial production industry, it's increasingly difficult to be wowed by developing technology. But SensAble Technologies' new FreeForm modeling system is an exception.

For years digital artists and designers have longed to model on the computer with the ease and intuitiveness of modeling with clay. Until now, they've had to use real clay or blue foam to sculpt conceptual models that are difficult to build on the computer, digitize these models, and import the data into a modeling package for further development.
The FreeForm modeling system, which includes the Phantom force-feedback device (left), allows designers to create digital models using their sense of touch.

FreeForm changes this workflow. The system, which combines new modeling software with the patented 3D Touch capability in SensAble's Phantom force-feedback interface, enables digital modelers to intuitively interact with images on the computer screen. With FreeForm, modelers can work from conceptual sketches, 2D drawings, scanned models, or 3D engineered parts to "sculpt" their models directly on the computer, using an armature-like stylus. Then, with the FreeForm modeling software, they can refine their models and add details, using many of the tools typical of computer modeling, such as cut, paste, and scale. Because the software takes into account the digital model's density and programmed physical properties, users can "feel," via the system's force-feedback technology, the 3D digital objects they're building on screen. After the modeling process is complete, users can translate their models into polygons or IGES curves that can be transferred into an animation program for skinning and rigging.

FreeForm also offers tools for carving as well as "pushing and pulling" data down to the level of adding skin texture. And it offers a Mirroring function that can potentially cut modeling times by making it possible to model one side of an object or character and then, with the click of a key, instantly complete the reverse side.

Although Freeform is an amazing tool, it is slow and therefore doesn't quite fit into the production pipeline at the production studio where I work. The more detailed the model becomes, the more difficult it is for the computer to complete simple commands, such as Rotate Image.

The other main limitation is that using it is somewhat akin to sculpting with a rotor tool and a caulk gun. The software hasn't achieved the subtlety needed for the kind of detail we demand in this business. It needs more soft-edged tools to prevent hours of smoothing and detail work after the model is blocked out.

Furthermore, there is a large spatial difference between the location of your tool and the object you're working with onscreen. Getting used to the necessary hand-eye coordination can be tricky. And while I'm on the subject of a wish list, it would be cool if SensAble would create a mouse-like tool, perhaps a trackball, that enables users to rotate a model with one hand while sculpting the model (using the stylus) with their right. This would complete the simulation of sculpting in a 3D physical world.

A new Freeform is on the way. While writing this review, I had the opportunity to test a pre-cut of the next version, scheduled to ship next year. It addresses several of the limitations of the first version.

First, the general workflow of the new tools is much better, and SensAble has optimized the code so that the program can handle more complex commands without slowing down. In addition, SensAble added auto-smoothing features to the original Sculpt tools, as well as a new tool called Attract that pulls the surface toward the tool and allows for fast, smooth blocking of a shape. And finally, interactive smoothing tools along with a global deformer feature improve the control and subtlety of the program. All these improvements should go a long way toward making FreeForm a feasible tool for production studios.

Although FreeForm isn't perfect today, I think it has the potential to revolutionize the future of modeling for users in several applications, including toy manufacturing, industrial design, and entertainment. Nothing else on the market attempts what SensAble is trying to do for the modeling industry.

Michael DeFeo is a senior modeler with Blue Sky Studios (Harrison, NY). He can be reached at

Price: $15,000 (includes haptic interface and modeling software)
Minimum system requirements:
Dual Pentium II 300MHz processors; 512MB of RAM; Windows NT 4.0 SP4; high-end graphics card with 32MB of RAM; hardware-based OpenGL acceleration.
SensAble Technologies
Cambridge, MA