Attached Link: http://www.daz3d.com/pages/broker/brokerreq(pict).html

Poser pretty much ignores the s line in an obj file. Knowing this ahead of time, you can make your model with beveled edges or coplanar edges. See the link above for an illustration on DAZ's site.

It's difficult to do this with after the item is already modelled, and a simple solution is, converting to obj, and then take it into UVMapper and "split vertices." This will un-weld all the polygons which stops the smoothing process and gives nice sharp edges.