I am about to do a green-screen shoot involving some moving and also zoomed camera shots with actors.
I am just wondering what are the minimum number of tracking points I need to have in the camera’s view at any given moment in order to use Blender’s tracker?
I also read somewhere that the tracker has problems with fixed camera shots, such as zooms. Has anyone had experience with this and found any way around it?
Many thanks in advance,
Tupik
You need a minimum of eight tracking points. And yes, it’s currently limited to shots with perspective shifts.
EDIT: Just to be clear. Tripod/zoomed shots are possible, but there need to be a certain amount of parallax in the shot for that to work.
one of sabastian koenig’s tutorials on blendercookie.com talks about tripod shots. i think his solution was to have some lateral movement before and after the tripod type shot so that the tracker can establish the relations between objects before the tripod shot. all of this is a bit vague to me at the moment, but take a look at his tutorial.
Fantastic! Thanks so much for your replies. Will check it out.
I assume that having 8 tracking points on the same plane (a greenscreen) is not a problem? Or do I need some points in the foreground too?
Cheers
It depends on your greenscreen setup and the camera motion. Ideally you would need something in the foreground/floor to track as well. Otherwise there might not be a perspective shift to base the solve on.