Me gladly offers solution; And this also improves greatly your performance.
Forgive me to simply cut'n paste this part from many previous attempts to
TIP people about this great item
Foreword:
I was also using drivers 4.9 and noticed this noisy edge effect. Kinda snow.
It's named by some as a specular defect. The Humus fix not only improves
the framerate of your Doom3 game; But will eliminate the specular glitch.
This has to do with, Humus changing the way the pixel shader computes
its value. This works for 9800Pro, but should fix also for the 9600/9700.
X800 families. Here it is in all its glory. I provide the ZIP link found in
europe, since the link on the original page does not work anymore, and
I don't have a WINRAR to open it.
--- Paste
THE Humus hotfix for ATI radeon renderer..
In case you missed the tweak. Here it is in ZIP format.
http://alexharis37.free.fr/doom/humusd3atitweak.zip
It's some sort of hotfix for the pixel shader to be ATI radeon friendly.
It does some float operations better, improves speed as well as
framerate. It also fixes specular glitches (pixies along some axis).
The speed gain to be expected is around 18%.. (Not on all ATI hardware)
To resume the principle; ATI 9800/X800 can compute things in
floating point mode much faster; as the original Doom3 methods
work well with NVIDIA cards; The original Doom3 pixel shader instruction
sequence is not friendly to the way ATI GPU works.. Humus noticed,
fixed it, and even talked to Carmack about it. Humus now works for ATI.
Not that ATI supports this fix, but damn IT WORKS !..
Just unzip in your doom folder and it'll create a glprog folder in the base
folder with interaction.vfp in it ... So this is not gonna break anything.
Doom3 knows how to load these extensions.
Read more about it here:
http://www.beyond3d.com/forum/viewtopic.php?p=342441#342441
AND since I'm here;
Let me tip you further for performance settings.
Most of us gamers hate that Vsynch OFF tearing look.
What is necessary to get unsynch performance and rock solid image is
to enable Triple Buffering.. That is done in your Catalyst driver under
the OpenGL section. Click Compatibility and enable triple buffering.
Now ingame, make sure Vsynch is OFF.. I repeat. OFF.
This not only makes the game look great, but improves performance
by another margin; slightly better than Vsych OFF alone.
With Vsynch OFF and Triple buffering enabled; You can set a more convenient
refresh rate; Way better than 60Hz, WITHOUT impairing your game performance
at all. In cas you don't have already a 'autoexec.cfg' in your doom3 base folder;
Create one and add this to it: It's TEXT.
seta r_displayRefresh "70"
This is for 70Hz... I personally like 85Hz better, even though higher refresh rate
steal a little bandwith to the fillrate and you may drop a fraction of fps going higher.
ATI cards with slower than 9800 fillrate will see a bigger hit when pushing the
refreshrate; but it's still rather negligible.
Should I tip you further and recommend you take every possible action to make
use of that 16xAF (anisotropic filtering).. I personally force it to 16 within catalyst,
and in Doom as well... This is like the right arm of HQ setting.. On a radeon 9800Pro;
16xAF will not drop the framerate significantly using the famous humus fix..
The overall textures as then SO So much better... Don't leave home without it.
Best regards to everyone who contributed to my understanding of these issues.
I recommend you all go browse alt.games.doom for more.
CHEERS !
(apologies for top posting, but the context is right IMHO)
N³o
