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

RealXtend vs. Second Life

Second Life overview http://wiki.realxtend.org/index.php/NG_Design_Document/Existing_Systems

Largest install base, most popular virtual world platform

Proprietary Viewer only is open source

Second Life Architecture

Monolithic

Very entangled

Two domains: Agent and Regionhttp://wiki.secondlife.com/wiki/Structural_Design_Overview

Architectures of both are identical

Consists of hosts, services, and stores

RealXtend Architecturehttp://wiki.realxtend.org/index.php/NG_Design_Document/Viewer_Architecture/Framework

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

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

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

RealXtend Architecture: Entity-Component

http://wiki.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

Scripting

Second Life Uses Linden Scripting Language Effects available immediately

RealXtend Uses Python Must reload

Both Need scripting privileges

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

Community

Second Life ~10m total residents http://wiki.secondlife.com/wiki/Scalability_VAG

RealXtend ~30,000

Use Cases

Similar for both Conferencing Games Simulation Socialization

Scalability

Second Life 50 avatars per region

RealXtend Unlimited number of entities

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?