Can materials be categorized by type?

[rborbone]

For example, can different metal materials be referenced more generally as "metal" when programming particle effects and sounds? I am making textures in substance painter so there are tons of different materials to reference in UE4.

[Kris]

Each material can have a a Physical Material assigned to it, which, in turn, can be assigned to a particular Surface Type.
The list of surface types can be accessed later.
e.g. If some hit result has returns with the surface type "Metal", create sparks.

[rborbone]

Absolutely fantastic. Works great! Thanks, Kris!