So, there’s a mask that was going to be used in H20 that I’m curious about. It’s appeared in some pictures from the movies and is on the cover of the EchoBridge DVD release and the Blu-Ray release of the film. I would like to know more about the mask - here’s the picture:
This should clear it up for you.
http://www.campblood.net/forum/index.php?topic=7978.0
Basically, once many Michael scenes were finished, the filmmakers felt the mask just wouldn’t do - particularly for close ups. They then hired Stan Winston studios to sculpt and create a new mask for close up shots. In one scene, rather than reshooting, they "CGI"ed a computer generated mask over the initial one. This move is somewhat controversial to some fans who felt the mask looks fake or hokey. Others do not mind.
I think they actually just painted a mask and basically matted over the mask instead of using actual cgi, sort of like rotoscoping back in the day. It looks like the mask was a matte and I believe I remember an interview where they denied it was drawn using cgi.