RE : Re: shockwave 3d and bsp trees

thank you very much 

Lucas Meijer <lucasmach8.nl> a écrit : peel peel wrote:
> hi,
>
> i heard that the best space partitioning system for old
3d engines are BSP trees but i wonder if it is suitable with
a old script like lingo
>
> i'm trying to use a BSP tree to perform polygon culling
and hsr and i'm a bit disappointed: lingo virtual machine is
such slow that recursive analysis of tree costs much CPU
than bytes freed by display optimisation
>
> i wonder if bsp is really useful for shockwave
engine... hsr and culling can be based on a more simple
sector/portal system, polygon optimisation is less precise
but lingo script doesn't have to perform recusrive searches
>
> do you think a simple sector-portal partition (and pvs
precalculated with raycasting) should be better?
>   
Anything that is not per polygon based, but per sector
(which will then 
have to be a model) is better.

Personally I don't really bother to do any extra culling
ontop of what 
shockwave3d already does for me.
One of the upsides of shockwave3d not having been updated in
all those 
years, is that it runs superfast on
modern cards, since we cannot use pixel shaders and all that
stuff...  
As long as you don't have a lot of different
models, those models can have a enormous amount of polygons
before 
things go bad.

I think that only for extremely heave poly scenes it makes
sense to 
cull, and then only if the scene is setup in
such a way that often you don't see a large part of it. In
that case I'd 
devide the environment up in models, (one model
per sector), and then turn those on off, based on maybe  a
pvs..  but 
pvs sounds very fancy for what that would be..
basically for all say 20 sectors, a list of what other
sectors you could 
possibly see...  so 20 lists of 19 booleans..

you could setup that pvs using raycasting and build a lot of
fancy 
stuff, but you're probably better off by just handwriting
this pvs based on your knowledge of the scene.

Bye, Lucas
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