A Platform for Distribution Virtual Environment

1
A Platform for Distribution Virtual Environment

• RENATA CRUZ TEIXEIRA
• OTTO CARLOS M.B. DUARTE

2
Introduction

• The aim of virtual distributed environments.
• The main limitations of distributed virtual
  reality system.
• Some samples of virtual distributed environments.
  SimNet Systems,
  EpsNET-IV, WOW

3
The Proposed Platform

• Platform Design.
• Platform Architecture.
• Service and protocol description

4
Platform Design

• Two goals Scalability, Flexibility
• Ensure consistency control in each group by a
  special host called leader.
• Divide the participants into multicast groups
• Adopt a distributed data model, partitioning
  virtual world data among its users.

5
Platform Design(continue)

• Uses three communications with different
  features.
• IP Multicast
• SRM
• TCP

6
Platform Architecture
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Service and Protocol Description

• The service primitives
• VR_Con.Req
• VR_Con.Ind
• VR_Con.Conf
• VR_Dis.Req
• VR_Dis.Ind
• VR_Update.Req
• VR_Update.Ind

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Service and Protocol Description(con1.)

• PDUs
• JR, JI, JC, LR, FNL, ES
• The Predicate_Action Petri Net model
• On sample of the model(enter the virtual world)

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Service and Protocol Description(con1)
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Service and Protocol Description(con2)
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Sample(Entering the virtual world)
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Simulation

• Simulation Infrastructure
• Simulation Model
• Measurements Performed

13
Topology Generation
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Simulation Model

• Parameters of Simulation Model
• DB initial size, Avatar size, Update size, Pm
• Detail of Simulation Model
• The virtual environment is divided into fixed
  areas.
• The environment is divided among all leaders
• The leaders.
• Participants movement

15
Measurements Performed

• Delay
• Transmission of a join request(JR PDU) to the
  leaders by SRM
• Waiting time due to leader reaction to the
  request.
• Establishment of a TCP connection.
• Transmission of the database by the TCP.
• Others
• The number of messages exchanged
• The number of handoffs

16
Platform Performance

• Partition of Virtual Environment
• Figure 1 --- Delay to enter the virtual
  environment and to perform a handoff
• Figure 2 --- Total number of handoffs for all
  participants
• Figure 3 --- Number of messages exchanged for the
  topology with 32 participants

• Participants speed

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Delay to enter the virtual environment and
perform a handoff
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Total number of handoffs for all participants
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Number of Messages exchange with 32 participants.
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End