Inhalt

•  
  Introduction
•  
   Motivation
•  
   Virtual environments
•  
   Distributed virtual environments
•  
   Large-scale distributed virtual environments
•  
   Overview of this work
•  
  Related work
•  
   Non-distributed VE systems and standards
•  
   OpenGL Performer
•  
   OpenInventor
•  
   VRML97
•  
   X3D
•  
   VR Juggler
•  
  Distributed VE systems
•  
   RB2
•  
   MR
•  
   DIVE
•  
   Repo-3D
•  
   MASSIVE
•  
  Research prototypes for scalable DVE systems
•  
   SPLINE
•  
   CVE (MASSIVE-2)
•  
   HIVEK (MASSIVE-3)
•  
   RING
•  
   NPSNET
•  
   Clustered rendering systems
•  
   WireGL
•  
   Net Juggler
•  
   Summary and discussion of related work
•  
  DVE Systems - A conceptual approach
•  
  DVE system requirements
•  
   Distributed object and event model
•  
   Display device abstraction
•  
   Direct-manipulation user interaction
•  
   Rapid prototyping and extensibility
•  
   Platform and performance considerations
•  
   From concept to architecture
•  
   Object model
•  
   Event model
•  
   Distributed object model
•  
   Distributed application layout
•  
   Distributed event model
•  
   Network transport layer
•  
   Data input and device interface
•  
   Scripting language selection and binding
•  
   Target platform considerations
•  
   Execution model: Single vs. multi-threading
•  
   A base system for low-level tasks
•  
   System API structure
•  
   Extension mechanism: API and link strategy
•  
   Avocado Architecture Summary
•  
  Avocado - implementation of the framework foundation
•  
   The Avocado object model
•  
   Mapping the field concept to Performer
•  
   Field containers for object state encapsulation
•  
   Smart pointers and reference counting
•  
   Adaption of Performer classes through subclassing
•  
   Field connections for event dissemination
•  
   Scene graph node classes
•  
   Sensor objects
•  
   An external device daemon process
•  
   Integration of the ELK Scheme language
•  
   A component interface for framework extension
•  
   An interface for state object persistence
•  
   Display device abstraction
•  
   Basic elements of the abstraction
•  
   Configuration examples for selected devices
•  
   Tool-based interaction support
•  
   An interaction metaphor for the Responsive Workbench
•  
   Implementation of the interaction abstraction
•  
   Extension through specialization
•  
   Summary
•  
  Avocado - implementation of the distribution architecture
•  
  Distributed object model
•  
   State sharing through object replication
•  
   The distribution group abstraction
•  
  Distributed event model
•  
   Distributed state change notification and event handling
•  
   Field connections in the distributed context
•  
  Guaranteeing application state consistency
•  
   The Ensemble/Maestro group communication system
•  
   Consistency through total message ordering
•  
   Synchrony through view atomic message delivery
•  
   Dynamic membership and atomic state transfer
•  
   Distributed locking through total message ordering
•  
   A simple distributed application example
•  
   Pacman: A complex distributed application example
•  
   Summary
•  
  Scalability in distributed virtual environments
•  
   Introduction
•  
   Scalability analysis
•  
   An environment model for scalability analysis
•  
   Analysis of existing systems
•  
   Comparison of tiling vs. no scalability mechanism
•  
  Exploiting visibility for rendering
•  
   View frustum culling in visual rendering
•  
   Level-of-detail evaluation
•  
   Hierarchical level-of-detail rendering
•  
   Exploiting visibility for distribution
•  
   Hierarchical environment partitioning
•  
   Mapping distribution groups to scene partitions
•  
   HLOD evaluation and the working set
•  
   HLOD evaluation and view frustum culling combined
•  
   Caching of inactive nodes
•  
   Implementation of the HLOD node
•  
   Scalability analysis of the hierarchical distribution approach
•  
   Summary
•  
  Results, applications and future work
•  
   Results of this work
•  
  Applications built with Avocado
•  
   Multi-modal interaction in virtual reality
•  
   Oil exploration demonstrator
•  
   PC-CAVE render cluster
•  
   Caveland
•  
   Commercial applications: Vertigo Systems and RMH
•  
   Suggestions for future work