Adding Force Feedback to Graphics Systems: Issues and Solutions William Mark, Scott Randolph, Mark Finch, James Van Verth and Russell Taylor Proceedings of the 23rd Annual Conference on Computer Graphics and Interactive Techniques (1996) Presented by Chris Covington

Force Feedback Simulates application of forces through a tactile (touch) interface or device. Simulates application of forces through a tactile (touch) interface or device.

Types of Force Feedback Non-interactive: Video game controllers, cell phones. Non-interactive: Video game controllers, cell phones. Interactive/restrictive: Tele-operation devices (PHANTOM). Interactive/restrictive: Tele-operation devices (PHANTOM).

Why Add Force Feedback Provides an additional sensory channel (haptic) for sending information. Provides an additional sensory channel (haptic) for sending information. Overloading a sensory channel (e.g. visual or auditory) can cause disorientation or loss of conveyed information. Overloading a sensory channel (e.g. visual or auditory) can cause disorientation or loss of conveyed information. More intuitive to perceive certain stimuli by touch. More intuitive to perceive certain stimuli by touch.

Feedback System Concerns Maintain high update frequency. Maintain high update frequency. Minimize artifacts and aliasing. Minimize artifacts and aliasing. Support different feedback devices transparently. Support different feedback devices transparently. Easily integrated with overall system. Easily integrated with overall system.

Latency and Update Frequency High latency causes inconsistent tactile feedback. High latency causes inconsistent tactile feedback. Disorientation and frustration is possible if tactile sensations do not correspond to visuals or acoustics. Disorientation and frustration is possible if tactile sensations do not correspond to visuals or acoustics. Force feedback devices may lose their “grip” unless they are refreshed. Force feedback devices may lose their “grip” unless they are refreshed.

Artifacts and Aliasing Occurs when force feedback does not match overall simulation. Occurs when force feedback does not match overall simulation. Feedback results should be consistent and repeatable. Feedback results should be consistent and repeatable. Can be caused by different update frequencies between haptic, visual and auditory systems. Can be caused by different update frequencies between haptic, visual and auditory systems.

Transparent Device Support Different types of devices have different capabilities. Different types of devices have different capabilities. Similar devices should act the same when interacting with the same system. Similar devices should act the same when interacting with the same system.

System Integration Integration should be easy and non- intrusive. Integration should be easy and non- intrusive.

Force Feedback Models Plane and Probe Plane and Probe Surface Friction and Texture Surface Friction and Texture Multiple Planes Multiple Planes Multiple Probes Multiple Probes Point-to-point Springs Point-to-point Springs Multiple Springs Multiple Springs

Plane and Probe Spring forces are applied to simulate different surfaces. Spring forces are applied to simulate different surfaces. Higher spring constants correspond to denser surfaces. Higher spring constants correspond to denser surfaces. Forces are always perpendicular to the plane. Forces are always perpendicular to the plane. Plane is constantly adjusted to provide different surface tangents. Plane is constantly adjusted to provide different surface tangents.

Surface Friction and Texture Simulates friction and texture through staggered movement. Simulates friction and texture through staggered movement. Accomplished through “snag” distribution over the simulated surface. Accomplished through “snag” distribution over the simulated surface.

Multiple Planes Difficult to provide feedback for sharp corners using only a single plane. Difficult to provide feedback for sharp corners using only a single plane. Multiple planes can provide smooth transition between surfaces and higher definition objects. Multiple planes can provide smooth transition between surfaces and higher definition objects.

Multiple Probes Provides multiple points of contact. Provides multiple points of contact. Necessary for more complex forms of manipulations. Necessary for more complex forms of manipulations. More complex, since each probe may interact with a different surface. More complex, since each probe may interact with a different surface.

Point-to-point Springs Allows objects to be picked up and dragged as well as pushed. Allows objects to be picked up and dragged as well as pushed. Complex spring evaluations limit the update frequency. Complex spring evaluations limit the update frequency. Could provide viscosity simulation. Could provide viscosity simulation. Multiple springs can provide torque simulation. Multiple springs can provide torque simulation.

Preventing Force Discontinuity Maintain high enough frequency to accommodate extreme motions. Maintain high enough frequency to accommodate extreme motions. Provide progressive recovery of embedded probes. Provide progressive recovery of embedded probes.

Armlib Device independent API for force feedback solutions. Device independent API for force feedback solutions. Uses TCP for command passing and UDP for feedback passing. Uses TCP for command passing and UDP for feedback passing.

Post-Paper Work Kitamura, Yoshifumi et al. “Object Deformation and Force Feedback for Virtual Chopsticks” (2005). Proceedings of the ACM Symposium on Virtual Reality Software and Technology: Kitamura, Yoshifumi et al. “Object Deformation and Force Feedback for Virtual Chopsticks” (2005). Proceedings of the ACM Symposium on Virtual Reality Software and Technology: Choi, Sam-ha, hee-Dong Chang and Kyung-Sik Kim. “Development of Force Feedback Device for PC-Game Using Vibration” (2004). Proceedings of the 2004 ACM SIGCHI International Conference on Advances in Computer Entertainment Technology: Choi, Sam-ha, hee-Dong Chang and Kyung-Sik Kim. “Development of Force Feedback Device for PC-Game Using Vibration” (2004). Proceedings of the 2004 ACM SIGCHI International Conference on Advances in Computer Entertainment Technology: Klatzky, Roberta and Susan Lederman. “The Perceived Roughness of Resistive Virtual Textures: I. Rendering by a Force Feedback Mouse” (2006). ACM Transactions on Applied Perception, Vol. 3-1: Klatzky, Roberta and Susan Lederman. “The Perceived Roughness of Resistive Virtual Textures: I. Rendering by a Force Feedback Mouse” (2006). ACM Transactions on Applied Perception, Vol. 3-1: 1-14.