How to remove smoothing (flat shading) and preserve when export/import to ue4

[levitikonL7F5A]

I'm trying to convert high-poly model to low-poly, the sort with faceted shading/flat shading/hard edges and the likes, and export/import into ue4. But no matter what I do, the import into ue4 results in smoothed shading. I need the faceted shading to be preserved somehow. I don't know if it's a 3ds max thing or a ue4 thing, so I'm hoping someone might have some perspective here.

Most everything I've found on the matter is actually about the opposite problem. About models being smooth in 3ds Max and being faceted when imported into other apps. I tried following along with those posts to try reversing the solution, but nothing panned out.

So here is the original model. Smooth as can be.

The original model

I learned I can produce the effect I'm looking for in 3ds Max by using ProOptimizer & Smooth modifiers:

ProOptimiser reduces to 10%Smooth with 0 threshold

This is great. It's exactly how I want it to imported into ue4.

So I export. I've tried all sorts of different combination of settings for both export and import to no avail.

A side note. When I re-import this back into 3ds Max by the way, it's smooth again. This is why I'm leaning towards it being a 3ds max thing.

And then I Import into ue4:

And this is how it looks. Smooth again.

[kdbusi]

try apply a edit normal modifier, select all ur normals and press make normals explicit before exporting, if does not work maybe try collapse stack too.

[krystian.slusarz]

Is this a skinned mesh? I've exported a mesh with smoothing groups and without em and it works fine.

[levitikonL7F5A]

You make that look so easy! It is a skinned mesh as it has bones and is a skeletal mesh in UE4. 

I'm curious what your export settings looked like?