[x3d-public] portal and cell graph LODing for X3D

[tom sparks]

Why has portal and cell graph LODing never become a feature of X3D?




* 
http://www.bitmanagement.com/developer/contact/examples/cell_portal/celllportal.html
* Interactive Walkthrough of Large 3D Models of Buildings on Mobile Devices
Alessandro Mulloni, Daniele Nadalutti, Luca Chittaro 2005?
* A Vrml97-X3D Extension for Massive Scenery Management in Virtual Worlds
Jean-Eudes Marvie, Kadi Bouatouch 2004