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Table Fog & 8-bit Paletted Textures

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Reply 101 of 224, by leileilol

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Joseph_Joestar wrote on 2021-11-15, 13:33:

Paletted textures seem to be a much more obscure issue. So far, I'm actually struggling to find games where the lack of that feature makes a clearly visible difference. Final Fantasy 8 being the one example that I have so far. If someone else knows of any other games where this is the case, feel free to share.

It's down to video memory and texture formats. Palettes' colors aren't restricted by 4, 5 or 6 bits, which gets around the 16-bit texture loss barrier. It's also a benefit for texture cache. Consoles were still using palettes for textures at the time, and often in a far smaller (16 indexes) palette, so using paletted formats in the PC ports (when they were supported at the time) would be logically analogous.

Usually the issues show up with anything using indexed alpha / chroma key, and or if it's a texture thrash from upconverting to RGBA (like a full multiplayer game of GLQuake with many different paletted players)

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Reply 102 of 224, by Gmlb256

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leileilol wrote on 2021-11-16, 11:57:

It's down to video memory and texture formats. Palettes' colors aren't restricted by 4, 5 or 6 bits, which gets around the 16-bit texture loss barrier. It's also a benefit for texture cache. Consoles were still using palettes for textures at the time, and often in a far smaller (16 indexes) palette, so using paletted formats in the PC ports (when they were supported at the time) would be logically analogous.

Usually the issues show up with anything using indexed alpha / chroma key, and or if it's a texture thrash from upconverting to RGBA (like a full multiplayer game of GLQuake with many different paletted players)

Yep, it was used for saving memory bandwidth at the time.

Reply 103 of 224, by rasz_pl

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https://developer.download.nvidia.com/assets/ … v/docs/Fog2.pdf

The RIVA128, RIVA128ZX and the RIVA TNT all emulate table fog using vertex based fog. The GeForce 256 supports table fog in hardware.

https://www.gamers.org/dEngine/xf3D/glide/glidepgm.htm

fog table should consist of 64 density values of type GrFog_t, which is an unsigned 8-bit quantity
that are logically viewed as fog opacity values corresponding to various depths. The table entries control the amount of blending between the fog color and the pixel’s color. A value of 0x00 indicates no fog blending and a value of 0xFF indicates complete fog.
The order of the entries within the table corresponds roughly to their distance from the viewer
If mode is GR_FOG_WITH_TABLE, then f is computed by interpolating between fog table entries, where the fog table is indexed with a floating point representation of the pixel’s w component.
To minimize “fog banding”, the Voodoo Graphics hardware linearly blends between adjacent fog levels within the fog table

Glide Utilities Library includes three routines that generate fog tables with different characteristics.
guFogGenerateExp() generates an exponential fog table according to the equation:
guFogGenerateExp2() generates an exponential squared fog table according to the equation:
guFogGenerateLinear() generates a linear (in eye-space) fog table according to the equation

so, where games require Table Fog do they mean the real 3dfx Table Fog where you can define your own lookup table? or the "Table Fog" as described in Nvidia document where you can only select between 3 predefined functions?

Reply 104 of 224, by Joseph_Joestar

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My Matrox G400 just arrived and I got the GeForce6 as well, so it's time for another round of testing. Once again this was my test system. However, the G400 refused to boot in that computer, so I had to test it using my Celeron rig. All tests were performed under Windows 98SE with DirectX 9.0c. No unofficial service packs or any third-party hacks were used.

Graphics cards tested:

  • Nvidia GeForce2 MX400 using Nvidia reference drivers v77.72
  • Nvidia GeForce6 6200 using Nvidia reference drivers v77.72
  • Matrox G400 using Matrox Powerdesk drivers v5.52.015

Note: for the purposes of this test, I will be using the same driver version for both Nvidia cards. This was done to take any driver related issues out of the equasion. As always, all driver settings are left at their default values.

Games tested:

  • Final Fantasy VIII Demo - you can download the free demo from here
  • Thief II: The Metal Age - retail CD version with the latest official patch 1.18 applied

Final Fantasy VIII configuration program

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The config tool detects paletted texture support on the GeForce2 but doesn't find it on the GeForce6, nor on the Matrox card. Fortunately, FF8 still allows all cards to run the game in 3D accelerated mode.

Final Fantasy VIII options menu

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To access this screen, start a new game, then press "D" to open the menu, move the cursor to "Config" using the arrow keys, and finally press "X" to open it. Since both the GeForce6 and the Matrox G400 show the washed out menu colors (same as the ATi card previously) we can conclude that this is indeed caused by lack of paletted texture support on those cards. The menu colors are rendered correctly on the GeForce2, and since it uses the same drivers as the GeForce6 for this test, we can narrow it down even further to paletted textures.

Thief II Mission 11: Precious Cargo

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As expected, table fog works fine on all of these cards. The GeForce6 series still supports it, and the Matrox G400 spec sheet states that it supports table fog in hardware. As you can see from the screenshots, the Matrox and GeForce6 cards render fog the same way as the GeForce2.

In summary, table fog support is functional on all three cards. And Final Fantasy 8 seems to be the definitive test for paletted texture support, since it checks for that feature in the config and also shows a visible difference when it's missing. If you want to test your own cards, feel free to download the FF8 demo linked above and try this for yourself.

EDIT - removed FilePlanet link.

Last edited by Joseph_Joestar on 2022-02-09, 04:21. Edited 1 time in total.

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PC#3: Athlon64 3000+ / Asus K8V-MX / GeForce4 / Audigy1
PC#4: i5-3550P / MSI Z77A-G43 / GTX 650Ti / X-Fi

Reply 105 of 224, by Joseph_Joestar

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During my tests, I have found that some rendering issues unrelated to paletted textures and table fog may occur in certain games. Some examples:

Dino Crisis - fence

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As before, both GeForce cards are using the same drivers here (v77.72) at their default settings, but somehow they produce very different results. This screenshot was made with filtering turned on in the Dino Crisis config menu. While turning this off fixes the fence rendering on the GeForce2, it doesn't change anything for the GeForce6. Matrox renders the scene correctly, regardless of whether filtering is turned on or off.

Dino Crisis - floor

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Notice the floor tiles with the debris on them. The GeForce2 and Matrox card render them correctly, while the GeForce6 has heavy distortions. Again, both GeForce cards use the same driver version here and turning filtering on/off doesn't change anything for the GeForce6.

Thief II Mission 1: Running Interference

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Both GeForce cards fail to render the stars in the night sky of the first Thief 2 mission. Matrox renders the stars correctly.

PC#1: Pentium MMX 166 / Soyo SY-5BT / S3 Trio64V+ / Voodoo1 / OPTi 82C930 / AWE64 Gold / SC-155
PC#2: AthlonXP 1700+ / Abit KT7A / Voodoo3 / SBLive / Vortex2
PC#3: Athlon64 3000+ / Asus K8V-MX / GeForce4 / Audigy1
PC#4: i5-3550P / MSI Z77A-G43 / GTX 650Ti / X-Fi

Reply 106 of 224, by SaxxonPike

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Joseph_Joestar wrote on 2021-11-15, 13:33:

Paletted textures seem to be a much more obscure issue. So far, I'm actually struggling to find games where the lack of that feature makes a clearly visible difference. Final Fantasy 8 being the one example that I have so far. If someone else knows of any other games where this is the case, feel free to share.

Extreme G 2 (XG2) textures are all white when palette textures are not supported. The game uses them almost exclusively. This results in the entirety of the HUD being white blocks and much of the track geometry being more shaded flats of white. The game does support loading true color formats, but there's only a few of these.

Edit: while on the subject, the GeForce 2 MX, GeForce 3 and GeForce FX all have very poor text rendering in the intro. Despite the game using Direct3D to render, the only cards I own that seem to show the game properly are 3dfx. I have a Rage Pro kicking around that I might try just for completeness sake.

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Reply 107 of 224, by Joseph_Joestar

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SaxxonPike wrote on 2021-11-16, 16:49:

Extreme G 2 (XG2) textures are all white when palette textures are not supported. The game uses them almost exclusively. This results in the entirety of the HUD being white blocks and much of the track geometry being more shaded flats of white. The game does support loading true color formats, but there's only a few of these.

Cheers, I'll see if I can track that down.

Since ATi, Matrox and GeForce6 all don't support paletted textures, it's now a bit easier for me to check whether a rendering issue is the result of that, or something else.

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PC#2: AthlonXP 1700+ / Abit KT7A / Voodoo3 / SBLive / Vortex2
PC#3: Athlon64 3000+ / Asus K8V-MX / GeForce4 / Audigy1
PC#4: i5-3550P / MSI Z77A-G43 / GTX 650Ti / X-Fi

Reply 108 of 224, by vorob

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Guys, after some search i found that ATI X1900 will be the most powerful and most compatible card for old games, basically while geforce 6 was a trash card for retro games, ATI kept it all working up until dx10 card showed up. Thief is displayed perfectly here, with fog and stars. Also some 8-bit Paletted Textures games worked like charm. Any recommendations on further tests, maybe some tough games?

Reply 109 of 224, by vorob

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Tried Dino Crisis. For some reason game runs in 12 fps.

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Reply 110 of 224, by The Serpent Rider

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For some reason game runs in 12 fps.

Weird, but some PS1 games ran at very low frame rates. For example FF7 battle scenes run at 15 fps even on "recent" PC port.

Guys, after some search i found that ATI X1900 will be the most powerful and most compatible card for old games

But only in NT5.x environment. Both are not ideal.

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Reply 111 of 224, by Joseph_Joestar

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vorob wrote on 2021-11-17, 20:47:

Thief is displayed perfectly here, with fog and stars.

Are you using Windows 2000 or XP? As mentioned before, ATi cards will render proper table fog on those operating systems when drivers 7.11 or higher are used. But under Win98, you can only get the fog using tweaks, which doesn't look the same.

Also some 8-bit Paletted Textures games worked like charm.

Which games?

Any recommendations on further tests, maybe some tough games?

Final Fantasy 8 is the ultimate paletted texture test. Download the demo that I linked to earlier and see how that goes.

vorob wrote on 2021-11-17, 21:16:

Tried Dino Crisis. For some reason game runs in 12 fps.

I'm getting slightly above 30 FPS on all of my cards in that game, according to Fraps.

PC#1: Pentium MMX 166 / Soyo SY-5BT / S3 Trio64V+ / Voodoo1 / OPTi 82C930 / AWE64 Gold / SC-155
PC#2: AthlonXP 1700+ / Abit KT7A / Voodoo3 / SBLive / Vortex2
PC#3: Athlon64 3000+ / Asus K8V-MX / GeForce4 / Audigy1
PC#4: i5-3550P / MSI Z77A-G43 / GTX 650Ti / X-Fi

Reply 112 of 224, by vorob

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Joseph_Joestar wrote on 2021-11-16, 15:44:

Final Fantasy VIII Demo - you can still freely download the demo from Fileplanet

There are no download button, or I'm blind. The big one leads to spam exe.

But I found proper one: https://archive.org/details/FinalFantasyViiiDemo

Reply 113 of 224, by Joseph_Joestar

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vorob wrote on 2021-11-18, 07:48:

There are no download button, or I'm blind. The big one leads to spam exe.

But I found proper one: https://archive.org/details/FinalFantasyViiiDemo

The Fileplanet link works with the one button that's there. I do use AdGuard on iOS, so maybe I'm not seeing the spam you're talking about. The mirror on archive.org is more convenient though, so kudos for that.

BTW, you didn't answer the questions from my previous post. It's important to properly document these tests, if you wish to contribute. In particular, stating the operating system and driver version would be helpful.

PC#1: Pentium MMX 166 / Soyo SY-5BT / S3 Trio64V+ / Voodoo1 / OPTi 82C930 / AWE64 Gold / SC-155
PC#2: AthlonXP 1700+ / Abit KT7A / Voodoo3 / SBLive / Vortex2
PC#3: Athlon64 3000+ / Asus K8V-MX / GeForce4 / Audigy1
PC#4: i5-3550P / MSI Z77A-G43 / GTX 650Ti / X-Fi

Reply 114 of 224, by vorob

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Are you using Windows 2000 or XP? As mentioned before, ATi cards will render proper table fog on those operating systems when drivers 7.11 or higher are used. But under Win98, you can only get the fog using tweaks, which doesn't look the same.

Yes, i'm using Win XP here and driver 9xx or smth like this. There are Windows games that use palette textures and don't work properly under XP?

Which games?

I've got a complex answer for this. I was looking for most compatible laptop some time ago and bought Toshiba with Geforce 6600. This was trash. Any game in 16bit looked like trash (GTA 2, Deus Ex in 16bit, Thief II and so on. I've also checked this list https://nvworld.ru/faq/geforce-6800-game-limitations/ and Shadow Vault wasn't working on NV 6600.

But it's all working like charm on ATI X1400, X1600, X1800 and X1900. Yes, on Windows XP.

So I've made a conclusion that old games stopped properly working on geforce 6 and ati kept it's compatibility with old stuff up util their first DX10 videocards came up.

Last edited by vorob on 2021-11-19, 06:58. Edited 1 time in total.

Reply 115 of 224, by vorob

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Tried FFVIII, no idea how it should look. But from my point of view it's okay. What do you think?

In config menu I've got 8-bit error.

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Reply 116 of 224, by Joseph_Joestar

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vorob wrote on 2021-11-18, 22:33:

Yes, i'm using Win XP here and driver 9xx or smth like this. There are Windows games that use for or palette textures and don't work properly under XP?

Some games like the Need For Speed series work sub-optimally under WinXP, but that's mostly due to EAX. The good thing about ATi and WinXP is that you get correct table fog rendering, unlike with Win98. Can you do a fog screenshot using my Thief 2 saves attached earlier?

I've got a complex answer for this. I was looking for most compatible laptop some time ago and bought Toshiba with Geforce 6600. This was trash. Any game in 16bit looked like trash (GTA 2, Deus Ex in 16bit, Thief II and so on. I've also checked this list https://nvworld.ru/faq/geforce-6800-game-limitations/ and Shadow Vault wasn't working on NV 6600.

Yes, that matches my findings. ATi definitively has better overall rendering compatibility than the GeForce6 series, but this is not due to paletted textures. Nvidia has other, unrelated issues which cause distortions in games such as Dino Crisis on GeForce6 and higher.

vorob wrote on 2021-11-18, 22:53:

Tried FFVIII, no idea how it should look. But from my point of view it's okay. What do you think?

In config menu I've got 8-bit error.

Same as my Radeon 9000 then. Can you do a screenshot of the options menu as per my instructions above? I'm curious about the menu bar rendering under WinXP.

PC#1: Pentium MMX 166 / Soyo SY-5BT / S3 Trio64V+ / Voodoo1 / OPTi 82C930 / AWE64 Gold / SC-155
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PC#3: Athlon64 3000+ / Asus K8V-MX / GeForce4 / Audigy1
PC#4: i5-3550P / MSI Z77A-G43 / GTX 650Ti / X-Fi

Reply 117 of 224, by vorob

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And no fog screenshot. I've got wrong driver and fog is not working, i'll install smth newer and be back. It's 100% working on ATI, just some driver issue.

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Looks like menu is dirty, i've compared with other screenshots.

Any additional tests?

Reply 118 of 224, by Joseph_Joestar

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vorob wrote on 2021-11-19, 05:16:

And no fog screenshot. I've got wrong driver and fog is not working, i'll install smth newer and be back. It's 100% working on ATI, just some driver issue.

No worries, post the fog screenshot when you have a driver from the 7.11 to 7.xx range. Also, make sure that "Fogging" is set to "On" under Thief 2 Options > Video settings. People on the TTLG forums were pretty happy with the results, so I'd just like visual confirmation that it's the same fog rendering as on the 3DFX, Nvidia and Matrox cards.

Looks like menu is dirty, i've compared with other screenshots.

Yeah, the washed out background colors in the menu are the result of missing paletted texture support. Just like on my own ATi card, my Matrox G400 and the GeForce6. Thanks for confirming that it also occurs on ATi cards running under WinXP.

Any additional tests?

With regards to paletted textures and table fog, you pretty much only need Final Fantasy 8 and Thief 2 to do a conclusive test. For different rendering issues (unrelated to these two features), there could be other games, but that's beyond the scope of this thread.

PC#1: Pentium MMX 166 / Soyo SY-5BT / S3 Trio64V+ / Voodoo1 / OPTi 82C930 / AWE64 Gold / SC-155
PC#2: AthlonXP 1700+ / Abit KT7A / Voodoo3 / SBLive / Vortex2
PC#3: Athlon64 3000+ / Asus K8V-MX / GeForce4 / Audigy1
PC#4: i5-3550P / MSI Z77A-G43 / GTX 650Ti / X-Fi

Reply 119 of 224, by vorob

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I've installed Catalyst 10.2. I'll try 7.xx driver but it can be tricky since it's a laptop card and such old driver maybe won't work even with modding.

--

I don't understand. If FFVIII has dirty interface it means card is not displaying 8-bit palette colors properly, right? But Thief works perfectly. And other games from my list on nvworld.ru work perfectly.