Newsgroup: it.comp.hardware.video-3d
Titolo: Open GL per VIPER 330

Usciranno driver decenti per l'open GL?
Che differenze ci sono tra un gioco in OGL e uno in Glide?
Riuscira' a sfruttare bene l'open GL la Viper? 

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Vorrei dire a tutti quelli che hanno in mente questa domanda che da
quando e` uscita la viper 330 funziona benissimo in OpenGL sotto NT4,
infatti QUAKE 2 va da DIO!!!
Se GLHexen2 o GLQuake non vanno e` perche` sono stati fatti pensando
SOLO alla 3DFX!!!
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Che lo SFORZO sia con te... (now playing XWing vs Tie Fighter!)
Home page: 
http://www.cs.unibo.it/~abilli
ICQ Number: [2509239]

GLHEXEN 2 E GLQUAKE 2 FUNZIONANO BENISSIMO CON VIPER 330 E TUTTE QUELLE
SCHEDE CON NVIDIA RIVA128 .
GUARDA QUA!!!!
WWW.RIVA128.COM
CIAO
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La viper e' compatibile con le opengl
solo che...almeno in win95 ci sono dei drivers ancora in fase alpha
per cui ancora non spremono il chip riva 128 completamente post qui la
risposta di un e-mail che e' stata mandata allo sviluppatore dei
drivers opengl per il riva
 da come vedete si dice chiaramente che la versione attuale dei
drivers opengl per
il riva non implementa tutte le possibilita' di accelerazione che il
chip offre:
Il testo completo lo potete trovare qui....
http://tiger.tnstate.edu:8080/
My Question: 
Hey Nick, hope I'm not bothering you. 
I have a (possibly) stupid question regarding OpenGL and D3D. I think
you are qualified to answer this, if you aren't let me know. My D3D
framerates on the RIVA are extremely good, anywhere from 30 to 100 FPS
depending on the application. OpenGL framerates are somewhat lower,
albeit that all we have to go on is an engine programmed by id
Software that struggled to get 25FPS on my P120 in DOS. Point being,
is OpenGL the culprit? Too much overhead? Inefficient? Is D3D that
much better? I see benchmarks from cards that easily score double or
triple on similar configurations when using D3D vs. OpenGL (i.e.
Quake/2), meaning I get 75-80FPS in Jedi Knight, 40-50 in Turok, but
about 1/2 to 1/3 of that in GLQuake/2. If, let's say, there was a
benchmark program that used the identical textures, etc. but was
written in OpenGL and D3D. Could we expect the results returned to be
the same? I'm not faulting you or the hardware here, but I have to say
that there are many people scratching their heads over this, me
included. I'm not asking you to comment for publication, just to
satisfy my curiosity about the fundamental problem with the
implementation of OpenGL on the PC/Intel platform, speed. Do you know
of any other OpenGL benchmark/testing software that gives a different
point of view? 
Thanks for giving me a minute of your busy schedule! 
Felby
RUG/RivaZone 
Nick's Reply: 
There are not any inherent flaws in OpenGL that would prevent it from
performing really well on 3D accelerators. In fact, OpenGL was
designed specifically to accelerate 3D rendering via hardware, while
D3D originally came from a software-only 3D library. Then there's the
question about why RIVA does such a great job accelerating D3D, and
why OpenGL on RIVA isn't as much of a performance leader. The simple
answer is that we're not done with the software yet. The RIVA 128 D3D
driver is a highly tuned, incredibly efficient piece of software. The
OpenGL driver simply hasn't been around as long, and so we haven't had
time to tune it to the same level that we have the D3D driver. That's
why we call it an "alpha" driver. There's boatloads of performance
changes that we haven't finished implementing yet. When we do finish
them, we'll get them to our customers as soon as we can. The changes
should be really significant. Hopefully, we'll see much better
performance once we have them all working. 
As for why Quake2 runs so much slower, take a really good look at a
scene of Quake2 versus one of those D3D games. Quake2 has LOTS more
detail in the scene. Walk outside at the beginning of the first level,
and look at the two flags on the walls. They're flapping in the wind.
To do that, id has to use a lot of triangles and animate them during
gameplay. Effects like those flapping flags simply don't exist in Jedi
Knight or Turok. They cost a lot of CPU cycles. I think a more fair
comparison is to compare Quake1 to Turok as far as frame rates go.
True, Quake1 is still slower, but, like I said, we've still got a LOT
of tuning to do to the OpenGL driver. 
I'm pretty excited about how well I think we'll eventually be
accelerating the OpenGL applications... 
Cheers,
 


hai detto bene sotto nt4!!!!!!!quelli per w95 fanno schifo............
Ciao 
an...@myline.net