Hi I am making a level with a lot of simple beveled cube, and I don’t know if I should use one prefab of the simple beveled cube, build the level in unity with these and use occlusion culling or if I should build the level in blender then export it as one object then use occlusion culling.
Occlusion Culling won’t work if there is one huge mesh : The Unity occlusion culling use GameObject, it disable them based on their visibility.
So if you have one huge mesh (that is one gameobject in the hierarchy), it won’t ever get culled.
I would recommend using different object. The thing that you can do is still use a 3D app (like blender) but make different object in blender. When imported, unity will keep the blender hierarchy (in fbx anyway) and so occlusion culling will work.
Keep in mind this object-thing when deciding what doing as a whole and what spliting. for example each room could be separated, allowing the culling to be done on a per-room basis etc…
More info here :