-fixed the bug when two or more objects dosen't have materials.

Update the script to work with latest trunk. Still some bugs when "remember position" = On, but much better than before.

Added export of only renderable objects via outliner hide_render property and active layers. Also thanks to all those who helped bringing instances through their designs or advice: Conz, mont29, Campbell.

Render POVRay addon: Now using instances for objects’ data, to avoid having exported hundred times the same mesh/material…
Coded in collaboration with MauriciusRay.

object hierarchy (parent/child) support for X3D export, tested with dupli-groups, scaling, rotations.
keep this optional so exporting without hierarchy is still supported.

- use XML escaping rather then cleaning to for strings

still need to add some operator options