You have to make them in another application and apply them. Poser doesn't do raytracing (like Bryce), you can't get real reflections, and you also can't control how the map is applied (spherical, reguarless of how the item is UV mapped). I get the best results with a simple horizion-line map, incidently. If I recall correctly, .bvh files are motion files, sort of like a multi-frame pose.