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Hi,

A little background:

I'm getting back into games programming after years off, last time I made a game was on the Amiga 1200! LOL. I've been coding C and C++ for years so that bit doesn't scare me, I've got Visual Studio 2008, and I've just purchased the Dark Game Studio bonanza pack with Dark AI, Dark Physics, Extends Expansion Pack and Dark Lights.

I want to experiment with 3D scenes and actor interaction, collsion detection, physics etc... to get a feel for games programming again.

I did a course at University on computer graphics and I remember learning about BSP trees. The important bit about BSP trees being that only visible polygons are rendered, which for large complex scenes is essential for performance.

However, I've searched this forum and have seen people discouraged from using BSPs and told to use DirectX "X" models instead. Why is this? I'm assuming here that when these X models are rendered all of their polygons are drawn regardless of visibility, if so, surely it's impracticle to use an X model to draw an entire scene (level/map) due to performance issues.

I understand that maybe you could manually split the entire scene/level X models into chunks, then use your own logic to decide which ones to draw at any given moment, but surely this is what a BSP does, and much more easily?

Comments welcome, regards, Dan....

Probably because the BSP support isn't the highest. There were generally issues when trying to load such a map with DBP, and if I'm not mistaken, BSP support has been completely dropped by now.

Objects can be culled so that away-facing polygons won't be drawn, but yes, "forward-facing" polygons, hidden beneath other polygons / etc. will still be drawn.


That's right.
However, such calculations are generally not done in realtime, but rather before finalizing the game-ready worlds. The hidden polygons may then even be removed.

DBP has a automatic culling for off screen polygons however its not 100% effective with animated object or objects with shaders.
since the animation calculation runs even if the object offscreen and takes up cpu power. thats why BSP is not recommend by a handfull of people. because DBP does this for you.



it dropped for DBPx10, as said in the youtube video but it is still in DBP U7.0. am unsure about versons after this.

Ok thanks for the info guys. I've been doing some reading and found that what I need is an effective view frustum culling algorithm. I found this library that does lots of nice things in including view frustrum culling: Jegas Game Classes Version 3.0 Library.

Can anyone recommend this? It costs 30 dollars, but is it worth it considering you say that DBP already handles off screen culling?

Regards, Dan...