Re: [Plib-users] max number of surfaces per model

[Steve B. <sjb...@ai...>]

Alexander Rawass wrote:

> > > max number of surfaces per model?
> > > max total size of textures per model?

> So, what would you say to him?

I would say "this is nothing to do with me - please ask the question
on the TuxFleet mailing list".
 
The problem is that you might have a 66MHz 486 with no 3D graphics card,
or you might have a Freon-cooled overclocked 1.13MHz P4 that Intel
forgot to recall with a 4x AGP and GeForce-2-ULTRA.

The difference in performance is at LEAST 10,000:1 ...probably more.

So, what hardware are you allowing as your usable range?

How many of these ships are you planning to draw?

What range of frame rates do you think you can tolerate?

What LOD mechanisms will you use?

Do you think you will be fill-limited or poly-limited or bus limited
or CPU limited or .... ?

I think you have to run your application with cubes in place of space
ships - then again with 10,000 (tiny) random triangles - and see where
in that range is a 'reasonable' frame rate on the range of machines you
want to support.


> Please make the following assumptions:
> 1) the HudObjects using glut have been replaced or switched off and
> therefore
>    take up not much cpu time
> 2) my code that does the game logic takes up from 0.001 to 0.005 secs
> each frame
> 3) the rest of the time is ssgCullAndDraw

Well, if you want to run at (say) 30Hz, and you want quite a lot of
spaceships, I'd tell your artist to aim for 1000 triangles at the topmost
level of detail - and provide 200, 50 and 10 triangle versions also so that
on crappy hardware, they only see the 50 polygon versions when they are
up close - and the 10 triangle versions at a distance - but on really good
hardware, they'll see the 1000 triangle version all the way out until the
object covers just one pixel.
 
> I personally just cant image how many polygons a suitable object should
> have,
> how many polygons plibssg can render (if not slowed down by game code or
> huds)?

It's **MUCH** more subtle than that - the number of OpenGL state changes
makes a difference - the average length of triangle strips you are able
to form makes a difference....all sorts of factors.

No two games are remotely alike.
 
> > This answer may not satisfy you, so let me just explain with some
> > examples
> > what I mean:
> >
> > Have a look at the bee (data/bee.ac). It's my favorite model, it looks
> > so *cute* :-)

(If that's the one from Tux_AQFH, my (then) 7 year old son made it!)

My best advice is that the artist and the programmer have to work closely
together on this process.

The artist (being artistic) may want to put more polygons into planets
and nebulea and comets and 'gaseous anomalies' and have textured "Borg
tetrahedrons"...or he may want planets that are 20 triangle icosahedrons
(ick!) and 10,000 triangle ships....that's why he's the artist and you
are the 'mere programmer' :-)

There is no good answer to this.

-- 
Steve Baker   HomeEmail: <sjb...@ai...>
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