That's I call a morphologically right pant. This is one of the few true serious male clothing I have seen, it's "Dagon" for Daz's Hiro, and it can be seen and noticed there is "something" under the zipper, as this must be that way if we are rendering a male person and not a mannequin as you said. This doesn't look like a cardboard plain "unisex" clothing, but like a true pant with a male character in mind when modeled.