RealXtend vs. Second Life

1
RealXtend vs. Second Life

• RealXtend overview
• Main ambition http//wiki.realxtend.org/index.php
  /NG_Design_Document/Introduction
• Promote the evolution of 3D web
• Promote virtual world standards
• Open source
• Based on OpenSimulator
• Consists of viewer, Naali, and server suite, Taiga

2
RealXtend vs. Second Life

• Second Life overview http//wiki.realxtend.org/ind
  ex.php/NG_Design_Document/Existing_Systems
• Largest install base, most popular virtual world
  platform
• Proprietary
• Viewer only is open source

3
Second Life Architecture

• Monolithic
• Very entangled
• Two domains Agent and Regionhttp//wiki.secondli
  fe.com/wiki/Structural_Design_Overview
• Architectures of both are identical
• Consists of hosts, services, and stores

4
RealXtend Architecturehttp//wiki.realxtend.org/i
ndex.php/NG_Design_Document/Viewer_Architecture/Fr
amework

• Seeks to be robust, extensible, and flexible
• Three main elements Entity-Component (EC) scene
  model, core API, network protocol
• EC scene model Any component that contains
  arbitrary data can be added to a generic entity
• Core API implements basic functionality (e.g.
  display graphics, manipulate scene, user input)
• Network protocol Extensible and allows
  applications to define custom messages
• Three main technologies Qt, Ogre3D, and kNet,
  which implement core API and EC

5
RealXtend Architecture Modularity

• Consists of a number of modules, core and
  user-defined
• Modules implement a functionality or service
• Modules have a minimal dependency on one another
• Events are passed along hierarchy of modules

6
RealXtend Architecture Extensibility

• Modules/features implemented as plug-ins can be
  enabled/disabled at runtime and are not distinct
  to a particular entity
• Can easily add new module or override old module
  to add/change a functionality without having to
  change the system

7
RealXtend Architecture Entity-Componenthttp//wi
ki.realxtend.org/index.php/Platform_Extensibility_
Working_Group/Entity_Component_Article

• All objects on scene are represented as entities
• Each entity has a number of components (e.g.
  light, mesh, scripts, etc.) attached to it
• Concept of actions
• Write Javascript/Python code for entity to
  manipulate components

8
Scripting

• Second Life
• Uses Linden Scripting Language
• Effects available immediately
• RealXtend
• Uses Python
• Must reload
• Both
• Need scripting privileges

9
Graphics

• Second Life
• Uses prims
• Just now starting to support mesh
• RealXtend
• Uses OGRE 3D graphics rendering engine
• Supports meshes for avatar, terrain, objects
• Can display shadows and particle effects
• Can import scenes from Blender

10
Community

• Second Life
• 10m total residents
• http//wiki.secondlife.com/wiki/Scalability_VAG
• RealXtend
• 30,000

11
Use Cases

• Similar for both
• Conferencing
• Games
• Simulation
• Socialization

12
Scalability

• Second Life
• 50 avatars per region
• RealXtend
• Unlimited number of entities

13
Conclusions

• Depending on what definition you take of a
  virtual world
• Similar in a broad sense
• Both offer basic virtual world functionalities
• Different in terms of implementation
• Modular vs. monolithic
• Feasibility/practicability of using realXtend
  instead of Second Life?