Hi-FiMan wrote on Yesterday, 01:06:

Upon testing a 6600 GT AGP, 6800 GT AGP, 7800 GS, 7950 GT, and even a Quadro FX 3450 under Windows 2000/XP I noticed things always looked off in 16-bit color games. I first noticed something was wrong in Descent 3 with the "fog" and then I noticed it in almost every other game that renders in 16-bit color; BANDING. This banding was not present on everything like a card that does no dithering at all (GeForce 8+); it seemed to be present only on some textures such as transparencies and maybe some others. The other game I noticed it a lot on was Shogo. You could see banding on the mech arms and some of the skybox textures.

Interesting observations. It never occurred to me that there may be some variations in different games, or even certain parts of the same game. While I haven't tested 16-bit dithering extensively, I did sometimes check it while testing the table fog support of various GPUs. For example, here's how Thief 2 looks on a Voodoo 3 card:

And here's the same screenshot on a much newer GTX 650 Ti:

The color banding is very evident on the latter card. If anyone wants to run additional tests with Thief 2, the save file and testing instructions are available in this post. Also, here's how that game looked on my GeForce 6200 card back when I was running the fog tests.

Hi-FiMan wrote on Yesterday, 01:06:

The other game I noticed it a lot on was Shogo. You could see banding on the mech arms and some of the skybox textures.

Textures never get dithered, but it's possible that paletted textures got regressed here.

leileilol wrote on Yesterday, 23:15:

Hi-FiMan wrote on Yesterday, 01:06:

The other game I noticed it a lot on was Shogo. You could see banding on the mech arms and some of the skybox textures.

Textures never get dithered, but it's possible that paletted textures got regressed here.

IIRC this is exactly what occurred with the switch from the FX series to the 6000 series, pretty sure fog table also got nuked around this time with the newer GPUs, may have been earlier.

Games that use the Lithtec Engine are a good way to test both if I remember right. Same with games using the Dark Engine like Thief and System Shock 2.

leileilol wrote on Yesterday, 23:15:

Hi-FiMan wrote on Yesterday, 01:06:

The other game I noticed it a lot on was Shogo. You could see banding on the mech arms and some of the skybox textures.

Textures never get dithered, but it's possible that paletted textures got regressed here.

Yes, textures themselves don't get dithered. It's probably more accurate to say certain blend modes are not getting dithered along with certain types of fog. None of these cards support paletted textures though and I don't think Shogo uses them unless you specify 8-bit textures in the settings which I did not. Also, the Radeon X1900 XT running driver 7.11 renders everything properly with dither and that card also does not support paletted textures. Interestingly, the Radeon also allows me to use MSAA without mucking up the font as long as the alternate pixel center option is enabled.

Here's a silly question...
IF the hardware feature was missing, would that make the 6/7 series forever "dead", but with the 8+ having programmable shaders, theoretically they could reimplement the feature accurately?

Trashbytes wrote on Today, 00:46:

leileilol wrote on Yesterday, 23:15:

Hi-FiMan wrote on Yesterday, 01:06:

The other game I noticed it a lot on was Shogo. You could see banding on the mech arms and some of the skybox textures.

Textures never get dithered, but it's possible that paletted textures got regressed here.

IIRC this is exactly what occurred with the switch from the FX series to the 6000 series, pretty sure fog table also got nuked around this time with the newer GPUs, may have been earlier.

Games that use the Lithtec Engine are a good way to test both if I remember right. Same with games using the Dark Engine like Thief and System Shock 2.

Table fog works on GeForce 6/7; however, it just might lack dither but I need to double check that. Shogo uses table fog heavily and it shows up on GeForce 6/7. I should also add that the Matrox Parhelia does not support table fog at all.

When I get some time, I will upload some pictures to demonstrate what these cards are doing and not doing.

Hi-FiMan wrote on Today, 04:21:

Trashbytes wrote on Today, 00:46:

leileilol wrote on Yesterday, 23:15:

Textures never get dithered, but it's possible that paletted textures got regressed here.

IIRC this is exactly what occurred with the switch from the FX series to the 6000 series, pretty sure fog table also got nuked around this time with the newer GPUs, may have been earlier.

Games that use the Lithtec Engine are a good way to test both if I remember right. Same with games using the Dark Engine like Thief and System Shock 2.

Table fog works on GeForce 6/7; however, it just might lack dither but I need to double check that. Shogo uses table fog heavily and it shows up on GeForce 6/7. I should also add that the Matrox Parhelia does not support table fog at all.

When I get some time, I will upload some pictures to demonstrate what these cards are doing and not doing.

Honestly its been a while since I last looked into it all but Geforce 6 and 7 changed quite a bit under the hood from the earlier cards so its certainly worth running a few tests with the cards to determine exactly what was lost/changed.

Shogo and Thief would both work well for this as each engine will quickly let you test for changes.

Table Fog & 8-bit Paletted Textures