It turns out that the House of Mouse researchers had more up the ir sleeve at SIGGRAPH 2017 than we originally noticed: in addition to the compliant mechanisms, Disney Research was also demonstrating a new method for designing cable-driven mechanisms that could help artists and hobbyists add motion to 3D printed models of animated characters.
With the use of cable-and-joint assemblies, researchers can incorporate complex poses and motions in their physical characters, which can be 3D printed or created in other ways. These cable-driven mechanisms can replace joint motors, which aren’t suitable for all limb sizes. Disney Research also says the cable-driven mechanisms can be used to make functional robotic hands and other devices.
“The advent of consumer-level 3D printing and affordable, off-the-shelf electronic components has given artists the machinery to make articulated, physical versions of animated characters,” said research scientist Moritz Bacher. “Our approach eliminates much of the complexity of designing those mechanisms.”
The researchers behind the new cable assembly technique have already tested the process on “Fighter,” a 2D puppet-like model that can assume several desired fighting stances with the mechanisms. They also made a simple robotic hand and a gripper.
But the technique for generating these assemblies is actually much more advanced than it first appears. Users can design a 3D printable frame or assembly of rigid links and hinges, and then specify a set of target poses for those assemblies. Special software then generates a cable network that will be capable of effecting those poses, starting with potentially thousands cables, and then gradually reducing that number through a process of optimization.
Researchers used the technique to build their 2D Fighter, which uses just three cables to achieve its various poses. The software first generated 1600 cables, then optimized the setup to reduce the number to eight, before optimizing again to reduce the number to just three.
Benedict. “Disney Research Animates 3D Printed Models with Cable-Driven Mechanisms.”3ders.Org, 31 July 2017, www.3ders.org/articles/20170731-disney-research-animates-3d-printed-models-with-cable-driven-mechanisms.html.