Content area
Full text
The FreeForm Modeling System from SensAble Technologies is a device that employs a haptic interface. This means that the sense of touch plays a key role in the user's interaction with virtual objects. I had a chance to spend some time with the system and found it to be a strong candidate for this month's column.
How it Works
Instead of forming clay with your hands and then using a 3D input device such as a touch probe or laser scanner to create a 3D model, the FreeForm Modeling System allows the shaping of virtual clay in physical space. The hardware component of the system is called the Phantom Desktop, appropriately named as it takes up a space of only about 6 by 6 inches. The Phantom applies resistance to a stylus-like device connected to the unit via a swing arm. The stylus and arm combine to produce a full six degrees of freedom. When you probe at a virtual model with the stylus, the Phantom recognizes when contact is made and provides force feedback, thereby giving the sense that you have come in contact with a physical model, as shown in Figure 1. The stylus' movements are mapped to the computer screen and displayed in a software program, also called FreeForm, along with the virtual model being sculpted. Essentially, you are using a physical device to make a virtual model.
The Phantom stylus is usually held in the right hand and the computer mouse in the left (assuming you are right-handed). The mouse is still a critical element as it's used to select tools in the FreeForm software. For example, one tool may act as a putty knife, while another may push and pull material. The mouse is also used as a navigation device as the buttons, from left to right, rotate, pan and zoom, which makes these operations very intuitive.
Setup
The first state-of-the-art aspect of the FreeForm Modeling System is how easy it is to set up. The device went from being sealed in the mediumsized box it came in to on my desk with me sculpting 3D forms in about 30 minutes. The key to this speedy transition comes from not needing to set up complex origins, coordinates and xyz planes....