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Old 06-24-04, 07:39 PM   #1
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Join Date: Mar 2003
Location: Tulsa
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Arrow NV40 antialiasing sample patterns

I have been looking into the drivers, Finding out what modes are still usable. From 61.32 and forward.

I have been going through the Various Anti Aliasing sample patterns currently available to the Geforce 6 6800. This is what I have currently Discovered. For Reference sakes.

Note: Green Dots: Are Geometry sampling and green dots are texture sampling. Super Sampling does texture sampling. Hence why they are seperate from geometry sometimes in Nvidias Hybrid Modes. Texture sampling can effect Alpha Textures and improve overall scene quality unlike geometry sampling.

  • OGMS: Ordered Grid Multi Sampling
  • RGMS: Rotated Grid Multi Sampling
  • OGSS: Ordered Grid Super Sampling
  • RGSS: Rotated Grid Super Sampling

2x: 2x hasnt changed any. Same 2 Sample Rotated Grid Pattern Found on the Nv3x/NV2x Series. Quincunx Shares this pattern Sample

2xQ: Quincunx is a special anti aliasing mode that dates back to the Geforce 3 series, Its share the same sample pattern as 2x. However a post processing pixel sharing occurs on ramdac which can decrease edge aliasing., This can introduce a "blur" effect to the screen. Once heralded as 2x performance at 4x Quality, it effectively removes edges better than 4x OGMS but inferior to 4x RGMS, Performance is in line with 2x multisampling.

4x RGMS: Large Change, 4x Rotated Grid Multi Sampling. Does a much better Job at hitting Horizontal Edges. With Nvidias compression. This mode produces optimal Image Quality/Performance of all modes available within drivers.

4x OGMS: Legacy Mode from NV2x/NV3x line. Sample Patterns are aligned in an ordered grid pattern. While effectively hitting vertical edges. It does little against horizontal aliasing.

4x-9tap: Another legacy mode from the Nv2x/Nv3x line that was never officially supported. Similar to quincunx it uses pixel sharing post processing that reduces edge aliasing.. It does however cause a blur effect like quincunx.

4xS Still usable on the Geforce 6800, Same as Previous card. 2x RGMS + 1x2 Super Sampling. (Direct3d Only) Notice the green texture sample patterns which will improve overall scene quality. This mode is usually faster than 8xS by a few frames per second. (Ut2004 is an anomaly)

8xS Appears to be 4x RGMS + 1x2 SS, I was testing this mode and to be honest the Performance is definately there and usable in many situations. The pink sample pattern represent the super sampling and its overall effects on textures.

16xS The very first 16x mode ever available under a Direct3d Enviroment! It consists of 4x RGMS + 2x2 OGSS. Notice the 16 Grey Geometry samples and the 4 pink texture samples. This mode requires massive amounts of framebuffer usage. Owners of 256 meg cards might find this more usable.

16x Super Sampling: Another new mode available under Direct3d. This mode consists of pure 16x ordered grid super sampling. This mode fillrate and bandwith limited and will bring even NV4x chipsets directly to it's knees.

2x1 Super Sampling: 2x1 Ordered Grid Super Sampling. Good for Compatibility, Still available with a registry tweak tool. Only good for hitting vertical edges, Horizontal Edges will not be affected.(direct3d only)

1x2 Super Sampling:Similar to 2x1, Also good for compatibility. This pattern is designed to anti alias horizontal edges, It will not do anything to verticle edges.(direct3d Only)

2x2 Super Sampling: 4x Ordered Grid Super Sampling. This pattern does best against verticle edges, But also removes aliasing on horizontal edges as well(Direct3d Only)

Old 6x: Consists of 4x OGMS + 2x1 Super Sampling. This mode was one
of the initial NV30 launch modes. It was long since replaced, Since it doesnt
hit horizontal edges at all it is not very useful.

12x Anti Aliasing: Also Known as 6xS for Geforce FX users. Its combination of OGMS and Ordered Grid Super Sampling. Noticing this pattern leaves me to believe the Geforce 6800 still supports Ordered Grid Multisampling somewhere within the drivers.

Old 8xS(Broken): Geforce FX users 8xS Anti Aliasing. A Combination of 2RGMS with 2x2 OGSS. Notice the pink patterns as well. Much larger performance hit than Nvidias new mode. However it seems to sharpen textures better. Unfortunately with later forceware drivers, This anti aliasing is currently broken.

Nvidia once again has unchallenged legacy support for its Anti Aliasing methods.
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Last edited by ChrisRay; 04-17-05 at 06:54 PM.
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