How does game “optimization” work? Are people sitting there changing lines of code to more “optimal” ones? What is “optimized”?

Question

The recent The Last of Us for PC made me realize I had no idea what’s meant by “optimizing” a game.

Same with optifine in Minecraft improving performance. How do these things work to just make games use fewer resources?

In: 158

Answer 1

Yes, code could be optimized through decreasing algorithms complexity (for example you make fewer loops inside the loops and replace this with another construction), you can remove objects that are taking too much space or unnecessary calls, clean up objects as soon as they are not used, etc.

Also graphics can be optimized, by adding occlusion culling and managing the level of details, but I don’t know much about it.