Low Cost Virtual Reality Platform Done by: Peter Fang, Kevin Feng & Karen Wai Supervised by: Prof. Edwin Blake & Dave Maclay

Introduction VR is expensive Benefit of cheap VR: –Education –Museum –Medical –etc

High end VR Requires: –CAVE-like projection system –High speed graphics workstation –Stereo shutter glasses –Motion tracking device –Very expensive!

Aim of this project This project: –Cheap VR –PCs –Use high-end PC graphics accelerators –Distributed network –Explore the use of PS2 in VR

Work allocation 3 parts in this project: –PC VR subsystem (Kevin) –PS2 VR subsystem (Peter) –Distributed network subsystem (Karen)

PC-Driven VR subsystem 4 projectors Passive stereo Corner projection 3 PCs connected by distributed network system 2 Dual output display card Each display PC control 2 projectors to produce stereo effect

Control5.1 Surround Sound System L2 Display 1 Hub L1 Left 10/100 Mbps Ethernet R2 Display 2 R1 Right Diagrammatic representation of the PC-Driven Subsystem

Advantage & Disadvantage Advantage –Easy to implement Disadvantage –Higher cost

Development Torque engine used to construct VE MS VC++ Windows XP

Possible Experiments Compare PS2 and PC presence Compare PS2 and PC performance Different hardware configuration

Risk Delivery of hardware may delay Our strategy: –Schedule the implementation so only 2 projectors are required until the final stage Alternate the use of projectors for stereo and corner projection

PlayStation2-Driven VR subsystem 3 PS2 connected by distributed network No dual output on PS2 Can only produce stereo or corner projection with 3 PS2 2 weeks of investigation to decide which is more appropriate and feasible Goal: demonstrate feasibility of VR using PS2 Outcome: one VR demo using PS2

Development How to program a PS2: –Linux Kit –Consist of HD, Network adaptor, mouse, keyboard, Linux, cable –Available from

L1 Display 1 Left Hub R1 Display 2 Right Control 10/100 Mbps Ethernet Diagrammatic representation of the PS2- Driven Subsystem

Advantages & Disadvantages Advantage of PS2 –Low cost –Equal performance of hardware Disadvantage –No audio in the proposed VR system –High software implementation complexity

Possible Experiments Comparison with PC in hardware performance Comparison of user presence level

Risk 1 Lack of expertise in the department -> less support More difficult to program than PC because of different architecture Skills of PC programming cannot be easily transferred to PS2 programming Expect minimum system can be built Analysis of the system will constitute the major part of the project

Risks 2 –No game engine -> no easy programming –OpenGL slow on PS2 due to different architecture –Expect slow performance if no optimization in PS2 assembly –However, we try to demonstrate feasibility, therefore not a priority in this project –Confident that algorithm optimization will give us interactive frame rate with PS2

Distributed network subsystem PC driven VR system –2 displaying computers & 1 control PS 2 driven –3 PS 2 –1 for control, others for display Links by 10/100 Mbps Fast Ethernet

Problem Synchronisation –Imbalance CPU & Graphics card –Equal performance PCs but with different complexities for displaying scenes Need –Consistent frame rate –Synchronized display of graphics

Goal Synchronization of the different projector displays with mean out of sync of less than 0.1 second

Possible Experiments Performance analysis of the system in relation to # of computers Response time of the display PCs and synchronization overheads

Cost  Total estimated cost ≈ R  Detail in proposal Hardware Software Others 92% 6.5% 1.5%

Resources Hardware –3 PCs with dual output graphics card (R31000) –3 PS2s with Linux kits (R15000) –Projectors (R80000) –Monitors, Network cards, Polarising filters etc.

Resources Software –Torque Engine (US $ 200 ≈ R1652) –Windows XP Professional, Visual C++.Net Others –IP addresses etc.