Hi. I was reading some info about portals, and saw how many advantages they have. Combination of portals and BSP trees gives you a nearly perfect performance. Another words portals are great and everyone knows that. However, there is one disadvantage to them that I want to address, and hopefully solve the problem. Portals and sectors have to be defined manually by the level designer during the creation of the level. This brings a lot of limitations. To be honest, I don''t like the word "static". Anything that''s precalculated leads to limitations. I think at this point hardware is powerful enough to define the word static as "calculated at the loading time", but we simply don''t have the right to say "manually defined during the design time" with 750 mhz pentiums. What I am leading to, is that there must be an algorithm that allows to optimally generate portals at the time when the level is loaded. I am not going to discuss portals that change their location dynamically during the game (although it''s also a good discussion), but I would like to hear your ideas about generating portal coordinates at loading time. Please post any ideas you have.

You say that BSP trees combined with portals are nearly perfect. Yet you say that you dont like the word "static". I think you are overlooking that fact that BSPs are almost always static, so what is the problem with the portals being static? If the world doesnt change, there probably isnt any good reason for the portals that break up the world to change either.

I think I didn''t clearly explain what I thought.

When I said "static" I meant defined at design time, manually. Sure, BSPs are static, but they are precalculated automatically. That''s exactly what I want to do with portals, create an algorithm that will precalculate them automatically. It definetly requires a lot of math, and I can''t do it alone, that''s why I''m asking for ideas for this type of algorithm.