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maplexp

About Portal

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maplexp    122
I'm building a portal base renderer now. In one frame, If I label the portals and areas that have already been accessed, and just jump them when a second visit, it will lose some areas that can be seen in fact. If I don't label them, I'll get a stack overflow error. My question is what is the right condition to stop recursion. So I can access every visible portal and area, and avoid stack overflow error. Thanks very much! [edited by - maplexp on September 1, 2003 11:38:54 AM]

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OrangyTang    1298
Keep going until the portal is no longer visible, which includes view-frustum checking and (important but probably overlooked) front/back facing checks - if a portal is in your view but back facing, then don''t recurse though it, otherwise you end up going back and forth until your stack gives out :S

If you just draw a sector and flag it, then you loose the ability to do mirrors etc. easily. Although I had a hybrid portal engine that the front/back checking wasn''t appropriate, so i transformed a portals point by the associated matrix and stored it in a list. If already present then i didn''t render it (becasue its already been done).

Odds are the frustum and back facing checks will be good enough though.

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