Screenspace depth-based contast enhancement effect
I spent a little bit of time with the VDrift refactor code implementing this effect:
http://graphics.uni-konstanz.de/publikationen/2006/unsharp_masking/webseite/results.html
It’s kind of like a cheap version of the Crysis SSAO that isn’t very convincing as AO, but when it’s applied lightly makes for a good improvement in apparent image quality. The improvement is especially noticeable with flat-shaded objects. It’s about as expensive as a 3×3 PCF shadow filter. I turned off all of VDrift’s fancy graphics and took screenshots with the effect on and off.
The effect is difficult to see after jpg compression, but focus on the car’s back bumper. With the effect on there’s subtle shading between the back bumper and the track. Also, look at the big start banner and its left and right side supports — they have a little more “pop” now. In motion in the game it really does improve the image quality, but I’m not sure if it’s worth the expense, especially in the context of a racing game where you don’t notice it very much.
Screenspace depth-based contrast enhancement effect -- effect OFF
Screenspace depth-based contrast enhancement effect -- effect ON