It seems to work o.k., but with a skin-tight transparent-edged object, you probably don't get shadows. The transparent-edge part would have to stand off from the body before shadows would be obvious. As mentioned by bijouchat IIRC, when a transparent object is within a certain distance above an opaque object in Carrara, the transparency optics start to cause strange effects that may seem like shadows (e.g. the Poser transparent eyeball material is too close to the eye to work right in Carrara).