VR Juggler Technical Overview

1
VR Juggler Technical Overview

• A Virtual Platform for Virtual Reality
  Application Development
• Allen Bierbaum
• Iowa State University
• IEEE VR Tutorial

2
Who am I?

• Allen Bierbaum
• Work
• VR Juggler Team
• PhD Student
• Iowa State University Virtual Reality
  Applications Center (VRAC)

3
Objectives

• Understand VR Juggler architecture
• Knowledge of some technical details
• Introduction to future VR Juggler developments
• Please Ask questions!!!

4
What is VR Juggler?

• Open Source VR software development environment
• VR Virtual platform Application framework
• Developed at Iowa State University
• Project director Dr. Carolina Cruz-Neira
• 5 years of development
• VR Juggler team (3 people ?10 people at VRAC)

5
VR Juggler background

• Motivation
• Standard VR development environment that is
• Flexible extensible
• Maintainable
• Modular
• Cross-platform / Cross-VR System
• Freely available OpenSource
• Allow community involvement
• Extension and refinement
• Peer review

6
VR Juggler features

• Virtual platform
• Application objects and framework
• Performance driven
• Performance monitoring
• Flexible and extensible
• Modular
• Open source
• Cross-platform Irix, Linux, Win32, others
• Configuration system
• Parameterization of VR system components
• Run-time reconfigurable
• GUI vjControl

7
Virtual platform

• Separates system dependent and system independent
  components

8
Virtual platform Benefits

• Benefits
• Architecture and OS independence
• Handles cross platform issues
• Virtual platform scales
• Device abstraction
• Separates application from hardware
• Proxies handles to devices
• Defines an operating environment for VR apps
• The VP allocates resources and processing time

9
System Parameterization

• Juggler config chunks specify single unit of
  configuration
• Parameterize all configurable parts of system
• Edited with Java base GUI (vjControl)

10
(No Transcript)
11
Kernel subsystem Motivation

• Motivating needs
• System must be extensible
• Add new devices and graphics APIs
• System needs to be flexible
• Adapt to VR systems, multiple configurations
• System needs to be dynamic
• Changes at run-time, added modularity
• System must evolve over time
• App survivability

12
Kernel subsystem

• Microkernel architecture
• Controls the entire system
• Manages communication
• Internal Managers
• Core functionality beyond the scope of the kernel
• External Managers
• Provide an interface to the system that is
  specific to application type

13
Kernel subsystem Benefits

• Benefits
• Modular system
• Managers can be added, removed, and reconfigured
• Discourages monolithic architectures
• Mediator
• Captures interaction
• Synchronization
• Portability

14
Internal managers

• Input manager
• Display manager
• Config manager
• Environment manager

15
Input Manager

• Controls all devices in the system
• Updates the devices
• Allows users to request devices

16
Devices

• Base classes for all device types
• Extend system here

17
Device Proxies

• All Devices are accessed through proxies
• Proxies hide the true device type
• Allows code and configuration to be device
  independent

18
Device Factory

• All device types are registered
• Allows for dynamic discovery and loading
• Separates devices from the rest of the system

19
Display manager

• Contains all information about display windows
• Performs all viewing calculations

20
Other internal managers

• Config manager
• Holds (re)configuration requests
• Environment manager
• Communicates the state of the system

21
External managers

• Draw manager
• Sound manager

22
Draw manager

• Provides external interface for applications
• Allows access to API specific functionality
• Handles all details of the API

23
Other External managers

• Sonix Sound manager
• Generic interface for several sound libs
• More in later talk
• Future
• Area for extension

24
Application objects

• All VR Juggler applications are objects

25
Application objects

• Override methods of a pre-defined interface
• Derived class for each graphics API

26
Application objects

• Benefits
• Single interface between app and system
• Low-coupling ? Robustness
• Application survivability
• Allows for flexibility in kernel
• Run-time changes
• Application management
• Capture application in single unit
• Multiple applications

27
Run-time (re)configuration

• Most current systems
• Static configuration
• No way to modify settings at run-time
• Configuring system
• Test settings ? Change settings ? Restart
  application
• Run-time Configuration
• Configuration is done dynamically at runtime
• Run-time Reconfiguration
• Maximum flexibility
• Allows settings to change during execution

28
Reconfiguration interface

• vjConfigChunkHandler
• API for handling configuration requests
• Implemented by all Managers and some applications

29
Config Manager

• Pending configuration queue
• List of configuration requests
• Stored in queue until kernel attempts
  reconfiguration

30
Reconfiguration process
31
Reconfiguration benefits

• System setup and configuration
• Easier initial setup using interactive testing
• Reconfigure displays
• Change physical devices
• Application adaptation
• Application switching at run-time
• Configure applications parameters
• Model loaded, navigation method
• Robustness
• Graceful recovery from device or app failures
• Performance tuning
• Adjust configuration based upon performance

32
Dependency management

• Dependency checking between components
• Components needing checking register a checker

33
System interaction
34
System interaction (cont)
35
VR Juggler 1.1

• VR Juggler development direction

36
Motivation

• New abilities and research areas
• High-level tools
• Technological advances
• Fix design problems
• Yes, we actually made some mistakes

37
JCCL
Gadgeteer
Vapor
38
VR Juggler 1.1 Modules

• Current Modules
• Vapor System abstraction
• Gadgeteer Device management
• GMTL High-performance math
• JCCL Configuration
• VR Juggler VR virtual platform
• Sonix Sound management
• Tweek Common GUI framework
• This all used to be just VR Juggler
• Now the Juggler suite of tools
• More on the way

39
New features

• Vapor
• Serial port abstraction
• Gadgeteer
• Clustering
• Run-time device type extension
• Input from gfx windows
• Cross-platform device drivers

40
New features (cont)

• VR Juggler
• Revamped configuration GUI
• Window viewports
• OpenSG OpenSceneGraph
• Performer reconfigurability
• Kernel shutdown
• Tweek
• Palmtop interaction
• Sonix
• Sound management

41
High-level tools

• Many new high-level tools in the pipeline
• All part of the Juggler suite
• In development
• Collaborative networking
• Sonification
• User interfaces
• and more

42
Availability

• Latest version always in CVS
• Developer releases
• VRJ 1.1 DR1 on the way
• New website with documentation