Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion

Corners Don't Look Like That:

Regarding Screenspace Ambient Occlusion

Sean Barrett

2012-12-13

The real, physical Cornell box.

From Modeling the Interaction of Light Between Diffuse Surfaces, by Goral et al 1984 The real, physical Cornell box.From, by Goral et al 1984

Please, feel free to gather better data yourself and prove me wrong. If you do so I'll link to it!

Game developers are in love with screenspace ambient occlusion (SSAO). They're so in love with it that they do all sorts of crazy things. Amateur developers post screenshots where convex corners get brighter near the corner. Professional developers release games with bizarre halos and ugly artifacts (look at the floor behind the railing).

Even when they avoid those flaws, games with SSAO often still look wrong. And an easy thing to pull out from it: corners of rooms look weirdly dark.

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