Why Occlusion Culling Improves Game Performance

Video games often include large complex environments, which can mean a lot of unnecessary processing. Occlusion Culling is a solution!

Today’s Objective: Explain the improvements that Occlusion Culling (and Frustrum Culling) can have on performance.

Culling? What’s that?

It is very easy, as a beginner developer, to ignore Culling or not even know it exists or is useful.

But as the projects become larger and more complex, you need to know how to manage optimal performance for your end user, on whatever device they use.

Especially if you’re developing for mobile/handheld devices, as they generally have much higher memory/processing/management requirements than other platforms.

Why’s it important?

Culling, when referring to rendering objects, aims to significantly limit or completely remove unnecessary rendering calls for objects that are not within the user’s current perception.

If nobody will see it, why show it?

By using Occlusion Culling or Frustrum Culling, a Unity developer can stop the computer/console/mobile/etc from rendering objects that the player doesn’t need to see.

It is useful, when thinking of render culling, to think of things in a frame-by-frame basis:

The objects made inactive by culling are able to not take anywhere near as much resources during runtime. This leads to better performance, especially with larger/more complex scenes and/or lower-end devices.