I wonder if there are any ready made tools to load 3d files ( 3ds , lwo , dxf ... ) for internal worlds ( Doom / Quake type ) to generate game data for them , I mean telling the game about the walls , the stairs , walking areas and so on ( I'm not interesting in placing objects and enemies for now ) , also to export a new 3D fileformat that is more RealTime friendly ( divided in to sections for example )
In general my question is how do people usualy deal with this ?

Check the 'Level Editing' tutorial at www.flipcode.com

This tutorial explains how to generate game data using the Quake-II/Half-Life WorldCraft Editor.

Check also www.gamasutra.com for to learn how to write a game editor inside of Max 3.0 without touching a line of C code. According to Ridgeway, the language is easy, powerful, and a great resource for building custom geometry tools. MaxScript included.

[This message has been edited by Equimanthorn (edited October 17, 1999).]