I love the game Incoming by Rage. It's a fast paced, colorful, shoot-em-up, utilizing DirectX 5. It makes heavy use of translucent texture blending modes and has a maximum of a 16-bit color depth. This game lives in the unfortunate place where graphics cards either struggled with these features or were not very performant, as these blending modes were considered advanced features. Good feature support and performance was eventually achieved with the ATI Rage 128 and NVIDIA TNT series, but 16-bit dithering and mip mapping in this game were negatively affected for the Radeon and GeForce series. I have been experimenting with different driver settings to try and get this game to work on these later graphics cards.

ATI cards are the most compatible and will work correctly with mip mapping enabled as long as bilinear and trilinear filtering are disabled. But 16-bit dithering looks terrible; with pattern dithering looking awful and noise dithering appearing as a distracting, shimmering mess. I couldn't find any way to disable dithering, so the ATI experience was very disappointing.

NVIDIA cards seemed irreparable. Dithering looked great, but all of the HUD textures were destroyed by overzealous use of mipmaps. This could be mitigated by disabling mipmaps, but then textures would be unreasonably blocky and low resolution. However, I found a way to fix this in RivaTuner by modifying mipmap options not available in the display control panel.

In Incoming, enable mipmaps but disable both bilinear and trilinear filtering; either filtering mode overrides these mipmap settings and makes the HUD unreadable. In RivaTuner, adjust the mipmap LOD adjustment one tick to the right to 0.1 (this fixes the HUD textures) and uncheck "enable user mipmaps" (this fixes the red arrow textures). Both of these options together fix the UI and also provide great 16-bit dithering that ATI couldn't provide. There are some very minor texture rendering issues, such as the logo rendering oddly, and some of the HUD textures being offset slightly, but this is very minor and is not an issue when actually playing the game.

Although this was tested on the GeForce FX, it should work for any of the GeForce series. The Riva, TNT, and TNT2 don't have this issue and does not need any tweaking.

I would be interested in whether anyone thinks that these tweaks might be applicable to other games as well.