Hello I was reading some docs about portal engines, and I am really interesed in code a "simple" portal engine, but my main trouble is how to handle the level data using portal, I mean, dose any algorithm take an array of polygons, and generate automatically the portals for the level, or maybe need I to handle portals by hand? PS1: I am using 3D studio MAX 4 for my level data, and I really appreciate any help with this trouble. PS2: Dose anyone about one game level editor wich use portals? Thanks in advance.

A portal is generally going to be represented as a convex polygon. Portals are usually pre-generated and stored in the level file (note: I do NOT mean pre-computed PVS). One technique is to create a BSP tree and use polygonal sections of the splitting planes shared by two nodes as portals. You could also use some sort of hand-placed portal technique, I suppose. Some games'' level editors work by "carving" levels out of a solid block. Portals, in that case, are the intersections of the negative brushes.

Thank you TerranFury for your help, but about the "carving" method, I am using some scripts for MAX 4, to use it like the Qradiant quake editor, I mean, to build two rooms connected by a hall, I create three hollow cubes (rooms, and hall), and then use a cut brush to connect the rooms with the hall, so in this case I suppouse the portal are the intersections of my cut brush?

Thanks!