How to initialize an array of structures with a given size using Init

[Tuerer]

When initializing an array, you need to indicate the values with which the elements will be initialized. In your case you have an array of structs, where struct element is also an array. So you need to indicate that in your Init():

TArray<FMaterialsArray> Tmp;
TArray<UMaterialInstance*> emptyMats;
Tmp.Init({emptyMats}, 10);