Which camera property should be adjusted to optimize rendering of smaller 3D objects at far distances?

Adjusting the layerCullDistances property is essential for optimizing the rendering of smaller 3D objects at far distances. This property allows developers to define specific visibility distances for different layers of objects. When layerCullDistances are set, Unity can efficiently determine which objects are within the specified distance from the camera for rendering. This is particularly useful for improving performance because it prevents the rendering of objects that are too far away and too small to contribute significantly to the scene. By avoiding the rendering of distant small objects, which may not even be noticeable to the player, the overall rendering efficiency is improved.

In contrast, the other options have different roles. The cullingMask property controls which layers the camera should render, but it does not specifically manage distance-related performance. The viewportRect deals with the display size and position of the camera's view on the screen, which is unrelated to object rendering at distance. The nearClipPlane defines the closest point at which objects are rendered, but it does not impact how distant objects are handled, especially smaller ones. Adjusting layerCullDistances directly targets the optimization needed for rendering at far distances, making it the best choice in this scenario.