Rocks smoothing groups

Autocon

So I am trying to figure out the correct way to go about smoothing groups for rocks and I cant seem to figure out the proper use of smoothing groups just by looking at in game models.

I have been told to make sure to use proper smoothing groups to give the hard edge rocky feel so stuff isnt too marshmallow looking, but i realize now I have no idea where to use proper smoothing.

This wont involve zbrush/mudbox at all so its 100% hand modeled. Also will use a tiling texture so painting edge highlights is out.

Here is just a quick example from UDK I found. Not sure if this is just 1 main smoothing group or if different chunks have different smoothing groups. The tri count is realitivly low with lots of 90 degree angles without chamfers all over so it would make me think that it cant be a ton of different smoothing groups or you would have really harsh angles instead of the nicer, softer hard edge look.

Piflik

Just look at the model without textures and you'll see the SGs...I think it might be one single SG, but with the Normal Map it is not easy to tell, if not impossible...

Autocon

Yeah thats what I would like to do because as you said its not easy/near impossible to tell with normal maps on, but I cant seem to get UDK to show only the model on the premade epic items.

Even if i try and assign just a grey material to the model nothing changes be it in the little model viewer or in game.