Body/Limb Tracking setup for fire?

[ellis]

Hi :)

I'm setting up a shot where the actor is being set on fire. The first shot is locked off and starts at his feet so that's pretty straight forward but later he will be moving around and then walking through a camera move.

It's most likely going to be tracked in pftrack or syntheyes with the flames being creating in maya and some real flames comped in.

My question is the setup of the tracking markers on the actor.

Where should they be on this body?
should i have a certain amount? color ect
Any advice on camera setup? Its being filmed on a 7D, some of the shots will be over cranked to 60fps.

Any thing any1 can tell me about making sure i can get enough information from the footage would be a great help. I need to make sure as he moves the flames go with his momentum.

A good example would be the final scene in Crank 2


http://www.youtube.com/watch?v=v9eufzjwCDQ&feature=related

many thanks

Dave

[zoostory]

You probably want to put small dots on and around joints and about half way in between joints. Kinda depends on the distance of the shot... A few points visible at all times in key areas for an object tracker to hang on to.

Too many trackers and removal will be even more of a pain.

Since you're shooting 7D, why not do it once without any points, then once with, then you can decide which one works better. You may find you can grab an object track and massage it in without the dots, and save some time and $$$ on not having to do removal.

Also, with the 7D, watch for rolling shutter. I wouldn't move the camera around too much for this shot... rolling shutter wobble can make your rotomation darned near hell.

[ellis]

Thanks very much. Thats pretty much what i needed to know :)

thanks

Dave