I've noticed that on ships such as the NX class, wileys kelvin fleet and the xindi insectoid ship that there is no TNG shield bubble. Rather, weapons directly hit the hull but do no damage until the 'shields' are weakened.
I'm trying to replicate this on TMP ships and the NuTrek Enterprise (since those shields are again hull based damage limitation rather than an external bubble), but I'm not sure how it was achieved.
Any ideas folks?