In Houdini I can paint selection and just force this selected polygons to have cusped normals. Or do this procedurally. I think in 3dsmax you could use Edit Normals Modifier.
Compare how normals are pointing in attached image. From top to bottom: - with smoothing - no smoothing - weird smoothing In the weird one most of the normals are point straight up, that's why it fools you in thinking that it's one flat geometry. The faces that doesn't look flat have their vertex normals pointing in the…
Another image: - top one shows primitive/polygon normals (I think primitives in 3dsmax are called faces if my memory doesn't fail me?) of with two faces cusped by me - middle shows cusped vertex normals of two faces by me - bottom one shows vertex normals of original downloaded geo As you can see after I manually changed…