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Quake3 *.bsp vs *.3ds meshes

Posted: Fri Feb 20, 2004 6:24 pm
by User[0]
Is there any big reason i should stick with Q3 bsp maps instead of making my levels as *.3ds meshes and then loading them in Irrlicht and generate the Octree from them and apply my lightmap material ?

is there any speed difference from creating and rendering a scene node from a bsp or from a 3ds mesh ?

Thanks in advance..

Posted: Sat Feb 21, 2004 10:43 am
by patlecat
Yes there is. You can assume openly that no one in the 3d gaming business can sacrifice performance, so each decision is taken with care, especially this one. But I feel you lack the basic knowledge of these concepts. Read yourself into this, I mean BSP and Octree etc. there are many good resources online for this, Google them. It's just too much to explain here.

you could be right...

Posted: Sat Feb 21, 2004 11:14 am
by User[0]
First of all thanks for the reply..
But I feel you lack the basic knowledge of these concepts
well i can say that i know pretty much about these concepts , but i feel that you missed the poin and that's why instead of new question i will say this

I feel you lack the basic knowledge of how irrlicht loads , generates the octree and creates the OctreeNode from an external mesh.

So the question remains :wink:

Posted: Sat Feb 21, 2004 11:25 am
by patlecat
I see. Well if you know it so well, then I must say your question makes no sense. It's not about how irrlicht loads either format, the BSP and Octree rendering is the key decision, since by those technologies itself result the limitations even irrlicht cannot overcome!
My suggestion about reading yourself into those technologies remains you smartass :wink:

Posted: Sun Feb 22, 2004 8:10 pm
by Wolf Dreamer
Is one faster than the other when used then?

Anyone able to give a straight answer?

Has nothing faster than one of these ever been created?

I'm thinking if a faster way could exist, a major company like ID would've come up with it by now, and thus their .bsp format would naturally be the best. Does anyone feel otherwise?

Posted: Sun Feb 22, 2004 10:42 pm
by jugurdzija
correct me if i am wrong but i thought that you could basicly load any supported type of mesh into irrlicht and then use octree or build bsp-tree from it,but eventually when i try to build bsp-tree i got warning that i should use octree method instead cause bsp is buggy.so even if you load a *.bsp level it is been partitionized by octree method...so it is the same to load a 3ds or bsp as far as you use irrlicht....maybe i am wrong!?

Posted: Sun Feb 22, 2004 11:13 pm
by patlecat
Fully righto mate. I was surprised to see one could load a bsp-compiled map and render it with the Octree algo, but yes it's possible. Where the advantage of such a move lies, I cannot say yet.
BSP only unfolds its power when pre-compiled.

Posted: Mon Feb 23, 2004 1:28 am
by jugurdzija
well then i thought right that you can build bsp tree from any kind of mesh?
it will be cool if that feature would be supported in later versions of irrlicht!

Posted: Mon Feb 23, 2004 1:59 pm
by patlecat
Yeah but if you don't pre-compile the BSP maps, then you don't have any speed advantages. Using Octree with BSP maps seems on first sight not to take advantage of these speed optimizations either. But what is it's use then? Just to have 1 renderer within a mixed world? To omit the need for portals??

Posted: Tue Feb 24, 2004 1:52 pm
by Guest
Ever thought of an outside world with a large building which is built as bsp?

then you know why using octree with BSP has a use because BSP with the outside world would crash or run that slow that you can throw everything away :)

Posted: Tue Feb 24, 2004 1:58 pm
by Robomaniac
I found a great map online, kineterra i think, which was exactly that, 2 huge bases, with a mountain pass inbetween them. I got it at planet quatke i think.

Posted: Tue Feb 24, 2004 3:38 pm
by patlecat
Anonymous wrote:Ever thought of an outside world with a large building which is built as bsp?
then you know why using octree with BSP has a use because BSP with the outside world would crash or run that slow that you can throw everything away :)
Yes but this is not a portal system where you mix the rendering methods as far as I know. So in fact a bsp map would be rendered as Octree - No speed advantage.
But this is all wild guessing from our parts as long as en expert can tell us what this option really does. Is it an automatic portal system or is it not?