Additional optimizations 

Two additional areas where you can optimize your game is with level of detail and using static colliders. Both of these concepts are discussed in the sections that follow.

Level of detail

Level of detail refers to how much detail is rendered on any given game object. The greater the number of polygons, the greater the level of detail your game objects will have. In order to reduce render times, you should consider what elements of detail need to be part of the 3D model and which ones can simply be included in the texture.

There are also level of detail (LOD) models. This is when you use multiple models of the same object in a game, each with a different level of detail...