In the context of Unity graphics, what is "Culling"?

Culling is a critical optimization technique used in Unity and other 3D engines to improve performance by reducing the number of objects that need to be rendered in a scene. When an object is not visible to the camera—either because it is outside the camera's frustum or obstructed by other objects—culling allows the engine to skip rendering those objects. This is especially important in complex scenes with many objects, as rendering every object, regardless of visibility, can lead to significant performance degradation and reduced frame rates.

By implementing culling, Unity can focus processing power on only the elements that contribute to what the player sees, ensuring a smoother experience without unnecessary computational overhead. This is crucial not just for frame rate optimization but also for efficient memory management, as it minimizes the rendering workload on the GPU.

The other options refer to different aspects of graphical rendering or processing, such as texture quality, texture layering, and lighting effects, which do not pertain specifically to the concept of culling.