stop motion and blender

Hi I’m learning about stop motion with a teacher and i would like to do a little experiment with blender. The experiment consist in animate the puppet and then replace the head with a 3d model of the head, to expand the range of faces. I saw some videos with people moving a peace of cardboard and a computer tracks the cardboard and add a 3d model over. this would be much easier because you would have static frames. But have no idea how its done , so if somebody could throw me some links or clues, i would appreciate.
Anything tutorials more videos ,links or explanations, because i have no idea how blender´s sequence editor works .

You would need to take note of your camera settings and use a camera tracking program. Something like voodoo or voocat, as it’s now called, or Syntheyes. These programs create 3d tracking points which can be imported into Blender via a python script. You then use the tracking points to line up your mesh. Or, if the character isn’t moving, as you say, you could maybe just do it by eye. Then you have to consider lighting your character to match the image. . .

I think that this is what you were looking for. http://www.ash.webstranka.info/?cat=12
But motion tracking would probably be quicker in the long run… unless you are going to lots of different takes over a long period of time.

thanks for the replays i would study about using tracking and see if worth a try :smiley: