A New Interface for Navigating a 3D Experience

Immersive 3D doesn’t get any better than the KeckCAVES at UC-Davis.  With four projectors that throw a 3D image on 4 surfaces, 3 walls and the floor, the CAVE utilizes a tracking system that can track a single person and change the projection’s point of view based on the user’s orientation. Ensuring this 3D illusion follows your sight line, the tracking system is incorporated into a pair of active shutter 3D glasses.  The effect is both exhilarating and slightly disconcerting (at first).   This is just one of many interface options in the CAVE.

At the the Lawrence Hall of Science, we’re attempting to create a much cheaper version of this experience using a single, commercially available 3D flat screen that uses passive 3D. As we transition to affordable setups, we depend on the expertise of our UC Davis colleagues to help find budget concious and unique interfaces for our limited 3D visualization setup.  Burak, a postdoc at KeckCAVES, introduced us to the Razer Hydra, a dual controller, motion tracking system.  He journeyed down to the Lawrence Hall of Science to set it up(and to give us some new 3D data sets!).

Image of the Hydra Controller
The Hydra controller uses motion tracking to allow someone to interact with a 3D virtual environment.

Simply, it’s a two handed, wired Wii-mote that accurately monitors each controllers’ orientation.  Unlike the Wii-mote which tracks via an infrared camera and gyroscopes, the Hydra’s black and green ball (in the picture above between the two controllers) track the controllers within a weak magnetic field.  Each controller has an analog joystick and buttons on top for your thumb and two buttons for your trigger finger.  Overall, it’s a pretty neat system, but it takes some time to get used to.  Conveniently. the buttons are customizable, and the controller feels like an extension of yourself into the 3D realm:  you move forward, the cursors on screen move forward.  Twist your wrist, and the 3D cursor twists.  As the pictures below show, controlling GlobalViewer takes a fair amount of full body movement:  this makes sitting and manipulating a 3D environment difficult.  We would recommend setting the TV such that an average person’s eyes are level with the screen’s vertical midpoint when standing.

We’re exciting to use this new tool!  If you have any suggestions for other controllers (keep in mind, they need to be Linux compatible), leave a note in the comments.

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