Swimming Across the Pacific

By Tzu-Pei Grace Chen for Dr. Sid FelsHuman Communications Technology Lab, UBC

Outline of the Talk

• Motivations• Implementation and modification• Synchronizing• Conclusion• Future work

Why Swim Across the Pacific?

• Artistic reason• Scientific motivations

Artistic Reason

• “Swimming Across the Atlantic” (1982) by Alzek Misheff

• Almost 20 years later: Swim Across the Pacific

• The problem: how do you swim in a plane?

The Solution

• Swim in virtual reality• Swimming cage bolted in a plane• All passengers wear head-mounted

displays

Scientific Motivations

• Virtual swimming - not well investigated

• Previous work– walking/running e.g. Sarcos Treadport– flying/hang-gliding e.g. Dreamality– bicycling e.g. Peloton, Trike

• Virtual swimming? – e.g. Aquacave and Virtual Diver

Issues

• Swimming at the water surface level– swimmer moves in and out of air and

water– requires rapid changes of the synthetic

environment

• How do you simulate the feel of water?– wetness, more resistance, can’t breath it

Implementation of SAP

• Two major components:– swimming cage– graphic system

• Only considering front crawl and butterfly

• Video clips of the current system• Discuss of implementation in more

details later

The Swimming Cage

Modifications Made

The Virtual Swimming Environment

Linking the Real and the Virtual

• Polhemus fast track sensors for the limbs

• Head-mounted displays for the eyes

• Tcl/tk interface for user calibration and adjustment

Sensor Synchronizing

• Each sensor gives position x, y, z and orientation yaw, pitch and roll

• Implemented sensor data mappings for the legs, the eyes and the arms

• Avatar made of spheres and rectangular prisms with embedded angles

The View Point / The eyes

• Involves finding the vectors for camera orientation

• Yaw, pitch and roll with respect to world coordinates not sensor coordinates

The Legs

)cos(2222 bccba

The Arms

• S, W and E forms a triangle• Finduse the cosine rule• Finduse the sine rule

The Arm

• A cone of possible solutions• Specify the solution to lie in the

plane of SW and z-vector

Conclusion

• Current SAP system still in infant stage– design may suffice performance art– has deeper scientific implications and

research values

• Realist feel of water rely on advancement in haptic, olfactory and gustatory devices

• Large hurdle because swimmer is in air and water

Future Work• More realistic rendering of the VE

– landmarks & sea creatures– 3-D waves and water splashing effects

• Tcl/tk interface for calibration• Mechanics

– accommodate s-shape of arm strokes– additional sensors; cordless even better

• Move into the Cave

The End