I have seen many posts about this topic, but many are older and sometimes they contradict each other, so I wanted to ask again
Question
I have a level which contains a building with many rooms. These rooms have many repeating elements, and I am building this for a rather lower end device target group, so I would want to have the performance optimized as much as possible.
I started building the level with normal static meshes, then learned about instanced static meshes, which are supposed to kinda reduce draw calls by instancing the mesh once and then loading that instance once, meaning less draw calls.
Now after building the building with that I learned that ISMs dont have LODs and also I read on multiple posts, that duplicating a static mesh with Alt´+ J already creates an instanced version of a mesh, which now makes me feel like I either missunderstood sth or ISMs are only good for efficient level building with bigger, repetetive elements, and have no other bigger advantage.
So far carefully merging objects that are repetitive and not too much of a bottleneck for memory has proven to be the most efficient way of reducing draw calls, especially as ISMs seem to all still have draw calls for materials aswell
Now my question, at this point, what even is the difference between a static mesh and an instanced static mesh, and is there any reason to not just merge meshes into one where possible?