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Lukerd

Portal Engine Test Data

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Hi Everyone, I''m just about to start writing a portal engine, i''ve done Octrees and Quadtrees but I thought I''d try something different. The thing is I dont know how I''m gonna create test data. I can create levels using Q3Radient and rip the polygons from the .BSP but how do I create the portals? I''ve heard I can use the splitting planes created by QBSP to get the portals, how? I suppose I''d prefer to write a program to create the portals automatically, anyone know any good docs on this? Thanks Lukerd "To err is human, to really mess up requires a computer"

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QBSP creates the bsp ( faces and trees ) from the .map file. QVIS creates portals and visiblity information. It is a difficult process that I would not suggest tackling yourself. Instead you might should have a look at gametutorials for a tutorial for loading Quake 3 .BSP's

[edited by - Hawkeye3 on August 31, 2002 4:04:08 PM]

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I know what the programs do. I know that the BSP splitting planes created by QBSP can be used for (somewhat inefficient) portals. I just dont know how.

I''ve read the BSP tutorial on game tutorials, but the point of my question was I wanted to write a Portal engine, not a BSP engine. They''re 2 different things, although they can be used together.

Thanks anyway, anyone else know?

"To err is human, to really mess up requires a computer"

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The only other method I know to add portals is by hand, but that would require a different type of level format. For example, each area would be a separate room. Once you make several rooms you could connect them together, and where they meet would be portals. The only thing wrong with this is that you have to either make the portal faces match exactly or write an algorithm that makes faces that don''t line up split each other up. ( Like if smaller faces to be used for portals are attatched to a larger face ). This method is sort of hard to explain.

The engine would then be able to do quick visiblity calculations in game to see if the normal of one portal faces another,and if there is nothing between the two. No visiblity trees unless you absolutely require them ( For object visiblity for example ). For an example of this, look at Descent 3.

I know this isn''t what you are looking for but its the only thing I could think of. Also, the data used for visiblity is created during the bsp - process, saved, and then deleted.

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Hehehehe, welcome to the biggest problem with creating a portal based engine: test data

I''m currently looking into parsing unrealed brushes to accomplish this, but things are not looking good...

I''ll post back here as soon as I find out is this is a doable approach.

Danny

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