If the shadow bias doesn't fix it, this is due to the miniscule nature of poser's scene-space. basically, the shadows require too fine a calculation value in raytracing because they are too small. Try the shadow bias first, always, If it doesn't work, increase the total scale of all your objects in the scene, and it will vanish at about 10 times their current size. As for the shader work: Awesome work. thumbs up

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)