Hello. I want to understand is it important to use simple collisions for static meshes? For example I have a hammer:
yes its important , like almost everything !
Almost always you can simplify your object in a simpler structure.
You may even create 2 box collision, one for the vertical wood, one for horizontal metal.
simple collision made by unreal can be often used, but as you can see they
dont follow the shape of the object.
if you dont need too much precision , is okay to use them.
if you need full precision , make the collision yourself.
to maximixe precision but get a performance impact, you may use all the mesh to collide
This is called “use complex collision as simple”.
2 cube have only 16 vertices.
that hammer have a lot more like 80 ?.
i am not an expert on how much deep calculation goes, but
simplification are there for a reason , so 16 is better than 80 
Well, I think there are some pitfalls, because we have capsule collision and sphere collision and it still using for collision simplification. I would like to see some tests or data about influence on performance with STATIC objects. I think it’s important if you don’t planning to make game with advanced physics. We have a nanite after all, maybe there was something similar for collisions a long time ago. I can sacrifice 1 or 2 frames for better positioning of meshes.
P.S. hammer have 864 vert 
holy butterfly ! 864 ! XD
Sphere and capsule look like a nice option ,
i think that collision are super easy with that,
its just distance from the center of the capsule-line or center of sphere.
maybe the best collision are spheres.
But yea , Dont use complex collision with that hammer XD
you can also make your own collision mesh i think and use that.
