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Virtual Reality Development Kit

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Sylvester Nowak. Saul Rojas. Suzanna Yau. Mark Shirley. Faculty Advisor Hong Man. Abstract ... A hardware/software package that allows developers of VR ... – PowerPoint PPT presentation

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Title: Virtual Reality Development Kit


1
Virtual Reality Development Kit
  • May 7, 2002

2
Group No. 26
  • Dylan Walker Team Leader
  • Anna Alaimo
  • Sylvester Nowak
  • Saul Rojas
  • Suzanna Yau
  • Mark Shirley
  • Faculty Advisor Hong Man

3
Abstract
  • The Virtual Reality Development Kit (VRDK)
  • A hardware/software package that allows
    developers of VR applications access to
    inexpensive open-ended position-tracking hardware
    and multi-user network interface software.
  • The VDRK includes
  • Hardware Optoelectronic infrared (IR) sensors
    and supporting timing circuitry, microcontroller.
  • Detects body position via analog IR signals, A/D
    samples signals and triangulates.
  • Software Client-Server communication, client
    rendering
  • Integrates multiple users, Renders perspective to
    video output.

4
Abstract Block Diagram
  • Sensor Transmission Unit
  • Located on users body
  • High power IR LEDs
  • Power Supply
  • Sensor Reception Unit
  • Located off-body
  • 3 IR phototransistors
  • Sends 3 output
  • channels to MCU
  • Microcontroller
  • A/D samples 3
  • channel inputs from
  • SRU
  • Sends data to Client
  • Client Application
  • Read data from
  • serial port
  • Obtain user data
  • Exchange data with
  • Server application
  • Server Application
  • Connect with
  • authorized clients
  • Exchange data with
  • clients
  • Creates data bank
  • Rendering Application
  • Render video output in
  • proper perspective

5
VDRK Prototype
  • While many components of the VDRK were completed,
    hardware problems prevents the aggregation of
    these components into a unified prototype.
  • Completed
  • Client-Server network software
  • OpenGL rendering software
  • Timing circuitry for the on-body IR LEDs
  • MCU A/D sampling and serial communication
  • IR phototransistor reception response
  • Incomplete
  • Triangulation processing code
  • Integration of timing circuitry with on-body IR
    LEDs
  • Integration of network and rendering software

6
Client-Server Network Software (1)
  • Composed of two software applications
  • Client Application
  • Obtain data from client hardware
  • Perform triangulation calculations with obtained
    data
  • Exchange data with the server
  • Pass received data from server to rendering
    application
  • Server Application
  • Accept incoming connections and data
  • Create a data bank of client data and statistics
  • Create and send a unique data source for each
    client

7
Client-Server Network Software (2)
  • Client Application
  • Successfully implemented Berkeley Socket API to
    establish Client Server communication using
    Sockets
  • We have changed our design to include
    triangulation calculations previously planned to
    be performed by the MCU
  • Server Application
  • Successfully implemented a data bank to store
    user data and statistics

8
Microcontroller A/D Sampling (1)
  • MCU Micro Controller Unit
  • Perform A/D sampling on output signal of three
    phototransistors
  • Transfer result of A/D samples to PC
  • Complete code to program the MCU for A/D sampling
    and data transfer

9
Microcontroller A/D Sampling (2)
  • PIC 16F877 Microcontroller and LAB-X2 EV board
    used
  • 8 channel 10-bit Analog-to-Digital conversion
  • RS232 Serial Port interface
  • PicBasic Pro Compiler for high lever language
    programming

10
Microcontroller A/D Sampling (3)
  • A/D sampling
  • We have completed the programming code for A/D
    conversion and data transfer to PC using the
    serial port
  • We have tested A/D conversion using 3 A/D
    channels of the MCU

11
OpenGL Rendering Software (1)
  • Description
  • Allows user to virtually move and position
    himself in a rendered virtual room.
  • To further user immersion, the user views the
    room and its contents in his own perspective.
  • Rendered video output may be connected to a
    commercial head-mounted display.

12
OpenGL Rendering Software (2)
  • Two robots are placed in our virtual room for
    demonstration purposes
  • Each represents a user.
  • The software was developed with the intention of
    receiving an input file from the network
    application.

13
OpenGL Rendering Software (3)
  • Measured Prototype Performance
  • Collision detection is implemented so that users
    cannot move through walls or furniture
  • Local user position, such as limb orientation may
    be specified continuously.

14
OpenGL Rendering Software (4)
  • Prototype Performance Comparison
  • Contrary to initial software design, a users
    global angular position may only be specified in
    90 degree increments.
  • To test the rendering software
  • User position data may be altered through
    keyboard input.
  • Perspective can be switched between the two user
    robots within the room.

15
OpenGL Rendering Software (5)
  • Future Enhancements may include
  • Implementing smoother, more realistic turns by
    our virtual users. Currently, a user may make
    turns at 90 degree angles only, although his
    limbs are able to move in a fluid, life-like
    motion.
  • Integration with client network application.
  • Improved graphical user models.
  • Various settings and design for the virtual room

16
IR LED Timing Circuitry (1)
  • Our initial design for the infrared LED Timing
    Circuitry called for
  • This did not prove possible, due to lack of
    availability of a 1x64 demux.

17
IR LED Timing Circuitry (2)
  • The following alternative was implemented instead
  • This can be generalized for 2n LEDs with an n-bit
    counter

18
IR Phototransistor QSD724
  • Features
  • NPN Silicon Phototransistor
  • Package Type Plastic TO-18
  • Daylight Filter
  • High Sensitivity
  • Package material and color black epoxy

19
IR Phototransistor Response (1)
  • Improper functioning of the phototransistor
    components was the largest hardware problem
    encountered in our project.
  • It generated a roadblock to the integration of
    our hardware elements into a single package
  • Despite numerous biasing methods, we were unable
    to obtain a significant response of the
    phototransistor to infrared light.

20
IR Phototransistor Response (2)
  • After several weeks of troubleshooting with our
    distributors tech. Representatives, we were
    informed of a possible batch error in
    manufacturing.
  • We ordered the same components from a different
    distributor and tests were successful.
  • However, the range of linearity in response was
    less than expected.
  • We were able to arrive at an empirical fit of the
    voltage output as a function of IR LED distance
    over a larger range V(d) .0246 d-1.71

21
IR Phototransistor Response (3)
22
Financial Budget (1)
  • Cost of prototype VRDK
  • Direct labor and materials
  • Indirect labor and miscellaneous expenses

23
Financial Budget (2)
24
Financial Budget (3)
  • Total cost of prototype VRDK 33,600 303.10
    263.15 34,166.25
  • Compared to the estimated development cost
    calculated in December (39,000), the
    development cost of the prototype in actuality is
    5000 less. The main reason for the cost
    reduction is already existing equipment in the
    Electronics Lab (oscilloscopes, multi-meters,
    power sources, etc.).

25
Schedule Proposed Gantt Chart
26
Schedule Actual Gantt Chart
27
Rendering Software Demo
  • DEMO

28
Questions?
?
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