GoKawiil🌲 The best work is the work that never gets executed
Saints Row: The Third Remastered - my first shipped title. Steelport is a dense open-world city, but the game also has tight indoor corridors, jets, cars, and parachute sequences. Getting culling right across all of that was a real challenge. Shoutout to Timur Gagiev - absolute legend!
Intro
In the modern era of AI coding, “AI game generation”, DLSS 5, Unreal Engine 5, and phenomenal Gaussian Splat demos, people tend to think graphics and games are solved problems. “Just grab AI and start building games within days,” they say. Obviously that’s bullshit. The hard engineering work, knowledge, tradeoffs, and art direction are not going anywhere. Whether your game is 2D or 3D, realistic or cartoonish, set in a closed Mars base or an open-world zombie-infested New York, you still need to optimize it. One of the most important optimizations every game has used, and will keep using, is culling.
Good news: almost 80% of the optimizations I’ve seen over my career boil down to “don’t do extra stupid work when you don’t need to.”
Bad news: you still need to implement culling while balancing scene structure, game design, art direction, hardware limits, and performance budgets.
So this article walks through the main culling techniques used in modern real-time renderers. I’ll group them by category so it’s easier to see how they relate to each other. Almost every one of these techniques deserves its own article, because as always, the devil is in the details.
1. The Basics: Distance, Backface, and Frustum
These are the cheapest and most universally applied techniques. They catch the obvious cases before anything more expensive runs.
Distance Culling
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