I have a VR game that works actually really smooth right now. But I am still working on optimization practices. I have quite a few meshes in my scene that are the exact same and don’t move. With my experience in 3d it is always better to use instances in this case, instead of just duplicating a mesh. Does this hold true in ue4? Judging form my research, it does. But ue4 instance tools are clunky or non existent it seems? Maybe this has changed? It seemed a little complicated to even find documentation on instancing of static meshes. I have found some stuff about doing it in blueprint? Or can you just do something as right click and instance in the viewport.
By default, if you take an object from the content browser and use it multiple times then it will only be stored in memory once (instancing).
What can also effect performance is the number of draw calls, the more objects/materials you have the higher the draw call count, so if you have a lot of low-poly objects then it’s better to combine them and use more memory to reduce the number of draw calls. I believe though that the latest version of UE4 has a feature for doing some of that automatically, previously you had to manually combine things or use Blueprints which allow you to use the Instance Static Mesh feature where basically you can work with duplicates separately but when the game is running it’ll combine them to reduce the draw calls.