Here's something interesting, this has to do with Daz Studio.  It's been a long time mystery to me that shadows were suddenly "cut" in DS when I used raytrace shadows, as well as the ugly lighted line when using deep shadow map.  Always into learning something and experimenting, I went to work and did two sample renders.

1st render (both renders together since we're only allowed one upload... a very small one that is... at Rendo forums) has raytraced shadows set at 4.0, with shadow bias at default settings which is 1.00.  Look at her left shoulder and right arm , where the shirt's gaining in on her skin (and the bottom of the sleeve on her right arm), note the "chopped" shadows.  Then look in side the shirt, at her left arm, note the "light" line, looks like there was a gap in the shirt letting the light in.  Now look at the partial transparent part of the shirt.  Notice how you see a lighted part at the beginning, how shadows start about a half inch from the "belt" of the shirt, and how on the ripple of the shirt, the further away, the further up the shadow?  This was also a mystery to me when using partial transparent settings on clothes.

Now, look at the bikini, specifically on her right side.  Notice the "blahness" that leaves you to thinking with no outline or shadows?  Yes, I used UberEnvironment light for DS, that is, "IBL" in Poser language, which brings in occlusion, but the maximum raytrace distance wasn't high enough for an outside render (less things closed in on the subject of the render).  With the MTD set higher, the occlusion would've been more visable on the bikini edges, but I left it alone.

2nd render, shadow bias set to 0.10, now take note of her left shoulder, right arm, shirt, and bikini again.  Note how much more "outlined" they are and that there's no mysterious "gap light" in her shirt, and no funny ripple shadows.

Figured this would open some eyes here :)  BTW, no funny spots on the lower settings, thankfully.  That's another reason why I don't deal with deep shadow maps ;)

...wolfie