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3dfx Advanced Features
This tab contains advanced
settings/features that can be used with the graphics card when using Direct3D or
OpenGL/Glide rendering modes.
Listed below are the options available & what
they do, plus recommended settings. NOTE - Some of these options may not appear
if you are running Windows 2000, certain CPU’s or don't have the x3dfx drivers
installed, so disregard any
“missing” settings.
Direct3D Options
This section contains settings that you can use to
tweak display options for games/applications that use Direct3D for rendering.
Screen
Capture Toggle Key. This setting can be used to bind a key to
capturing screenshots with the Voodoo 4/5 in Direct3D rendering modes. If you
wish to use this ensure that the key selected doesn't not interfere with the
keyboard controls used in the application/game in question.
Screen
Capture Limit. This setting is used to set a limit on the Maximum
number of frames to capture when the Screen Capture Toggle Key is hit.
I'd recommend setting this to 1.
Screen
Capture Destination. This setting can be used to select the location of
where any screen captures are to be saved. By default this is in the
directory of the Application/Game being used.
3D Filter Quality.
Using this setting you can further improve image quality. The display image
can be filtered by averaging pixel values. Selecting High (uses 2 adjacent horizontal pixels from a line & the 2
pixels on the line below (a 2x2 box filter) to create 1 output pixel) will
result in more pixels being averaged, resulting in a sharper image. Selecting Normal
will average less pixels than High
(uses 4 adjacent samples on a line (a 4x1 linear filter) to create 1 output
pixel), resulting in a smoother, more blurred image. Selecting Automatic
will allow the program to use filtering as needed. I’d recommend setting this
to High.
Alpha Blending. This setting can be used to enable/disable
dither subtraction on the Destination colour during Alpha-Blending. When dither
subtraction is enabled, the dither matrix used to convert 24-bit
colour to 16-bit colour is subtracted from the destination colour before
applying the alpha-blending algorithm. Setting this to Automatic will allow the application in question to use dither
subtraction as necessary. Setting it to Sharper
will enable dither
subtraction, resulting in a sharper image. Setting it to Smoother will disable
dither subtraction, resulting in a smoother image. I’d recommend setting this
to Sharper.
NOTE – Setting 3D Filter Quality to High
& Alpha Blending to Sharper will enable the use of a
special post
filter (This article is for the Voodoo 5 although the Voodoo 3 uses the same
process) which results in effectively 22-bit colour. This will provide optimal
image quality with the Voodoo 3.
Geometry
Assist.
This
setting allows those of you with fairly new processors (Pentium 3, Athlon or
newer) to take advantage of optimized geometry processing paths on such new
CPU’s. This can improve performance &/or visual quality in many Direct3D
supporting applications/games. If
you have a Pentium 3/Athlon or newer select Enable (Reboot required) to enable
Geometry Assist in Direct3D. If your processor is pre-Pentium 3/Athlon, e.g.
Pentium 2 or K6-2 this option will not be visible.
Select
Disable (Reboot required) to disable Geometry Assist in Direct3D.
You should only select this option if any of your Direct3D accelerated
programs/games become unstable as a result of using Enable.
Level of Detail Bias.
Using this
setting you can make textures appear sharper or blurrier. This is quite useful
& can enhance texture quality greatly. The performance hit when using this
is negligible also. Valid ranges for this are –2 to 2.
Don’t set it higher than 0 though as image quality will be worse
(blurred) & there is no useful performance gain.
Here’s what the LOD bias does. LOD
bias modifies the calculation of texture level of detail parameter LOD. Often a
texture is oversampled or filtered such that the texture is band limited at
lower frequencies in one or more dimensions. The result is that texture-mapped
primitives appear excessively blurry. LOD bias provides biases in the LOD
calculation to compensate for under or over sampled texture images. Mipmapped
textures can be made to appear sharper or blurrier by supplying a negative or
positive bias respectively. I’d recommend setting this to 0 – 0.50
for optimal texture quality with minimal artifacts.
Maximum Buffered Frames.
This setting allows you to limit the amount of pending swap buffers.
Setting this too High can hinder your system's response to input
(Game Controller’s or other devices) as all of the pending swap buffers are
processed before the system proceeds to the next operation. However a Higher
amount of swap buffers can also lead to higher frame rates, but at the
same time increasing latency (waiting for the card to draw the frame). I’d
recommend leaving this set to 1 or 2
personally.
MIP map Dithering.
Using this setting you
can enable smooth transitions
between textures (more specifically, between mip-map levels). This will result
in improved image quality, although potentially reduce performance as dithered
mip-maps can’t be multi-textured. I’d
recommend setting this to Enable
unless you really need to increase performance, in which case set it to Disable.
Z-buffer
Optimization. As you can probably guess from the title of this
entry, setting this to Enable will enable an extension that
optimizes the use of the Z-buffer. This can improve performance. Try setting it
to Disable if you encounter problems running certain Direct3D
games/applications.
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