--- title: Corners Don't Look Like That: Regarding Screenspace... description: A photographic investigation into whether screenspace ambient occlusion (SSAO) accurately represents real-world corner lighting. The author took calibrated... canonical: https://daily.dev/posts/corners-don-t-look-like-that-regarding-screenspace-ambient-occlusion-u2j2rkdj7 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion | daily.dev og:description: A photographic investigation into whether screenspace ambient occlusion (SSAO) accurately represents real-world corner lighting. The author took calibrated... og:url: https://daily.dev/posts/corners-don-t-look-like-that-regarding-screenspace-ambient-occlusion-u2j2rkdj7 og:image: https://api.daily.dev/og/posts/u2j2rkDj7.png og:image:alt: Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion **[Hacker News](https://daily.dev/sources/hn)** · 15 min read · 0 upvotes · 0 comments ## Summary A photographic investigation into whether screenspace ambient occlusion (SSAO) accurately represents real-world corner lighting. The author took calibrated photographs of room corners under various lighting conditions, sampled pixel brightness values across edges, and graphed the results. The findings show that real-world corner darkening is subtle, often barely measurable, and frequently what appears to be corner darkening is actually a perceptual Mach banding effect or the result of soft shadows rather than true ambient occlusion. The author argues that SSAO implementations typically over-darken concave corners, producing unrealistic results, and that the only time strong edge-darkening occurs in reality is when the facing surface is already darkened by another cause like a soft shadow. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Does screenspace ambient occlusion accurately represent how corners actually darken in real rooms? Photographic measurements of pixel brightness across wall and ceiling corners show that genuine edge-darkening is usually subtle and inconsistent, contradicting the strong, uniform darkening typical SSAO implementations produce. Most visible corner darkening in photos traces back to soft shadows, direct lighting falloff, or Lambertian dot-product effects rather than a general ambient occlusion phenomenon, and sometimes perceived darkening is just Mach banding rather than an actual brightness change. _Developers weighing how much AO darkening to apply can compare notes on rendering realism via daily.dev._ ### What causes the halo and dark-corner artifacts often seen in games using SSAO? Bizarre halos and dark ring artifacts around objects arise because developers assume corners of rooms are inherently dark and tune SSAO to produce strong darkening near convex and concave edges, when real photographic evidence shows this darkening is often much weaker or caused by other lighting phenomena like soft shadows rather than occlusion itself. _Anyone debugging SSAO artifacts in a renderer can find related graphics deep dives through daily.dev._ ## Similar posts on daily.dev - [Spatial hashing for raytraced ambient occlusion](https://daily.dev/posts/spatial-hashing-for-raytraced-ambient-occlusion-muvefftbp) · Interplay of Light · 0 upvotes · 0 comments --- Tags: [#game-development](https://daily.dev/tags/game-development), [#graphics-programming](https://daily.dev/tags/graphics-programming) [View this post on daily.dev](https://daily.dev/posts/corners-don-t-look-like-that-regarding-screenspace-ambient-occlusion-u2j2rkdj7) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion","url":"https://daily.dev/posts/corners-don-t-look-like-that-regarding-screenspace-ambient-occlusion-u2j2rkdj7","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/corners-don-t-look-like-that-regarding-screenspace-ambient-occlusion-u2j2rkdj7"},"datePublished":"2026-07-20T16:20:09.970Z","dateModified":"2026-09-13T20:05:23.594Z","description":"A photographic investigation into whether screenspace ambient occlusion (SSAO) accurately represents real-world corner lighting. 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Most visible corner darkening in photos traces back to soft shadows, direct lighting falloff, or Lambertian dot-product effects rather than a general ambient occlusion phenomenon, and sometimes perceived darkening is just Mach banding rather than an actual brightness change. Developers weighing how much AO darkening to apply can compare notes on rendering realism via daily.dev."}},{"@type":"Question","name":"What causes the halo and dark-corner artifacts often seen in games using SSAO?","acceptedAnswer":{"@type":"Answer","text":"Bizarre halos and dark ring artifacts around objects arise because developers assume corners of rooms are inherently dark and tune SSAO to produce strong darkening near convex and concave edges, when real photographic evidence shows this darkening is often much weaker or caused by other lighting phenomena like soft shadows rather than occlusion itself. Anyone debugging SSAO artifacts in a renderer can find related graphics deep dives through daily.dev."}}]} ```