AE CG Object Positioning

[Brett]

i have a shot of a grenade blowing up from a distance behind a snipers point of view. unfortunately i paned the camera towards the sniper as its blowing up, I use AE every now and then but what im trying to do is have the explosion stay in the same place as the camera is paning....is there an easier way to do this besides keyframing ever part...i dont mind keying it but it jumps everytime because i can never get it in the exact same spot as it pans...

 

[Arson]

either stabilize the shot and then place it then reverse the stabilization
or
track multiple points that maintain visiblity and then use that track to pin down the explosions position and rotation.

I think this tutorial although an eye replacement should be the same or similar method. you might need to keyframe stuff if your footage is such that anything you tracked it goes off screen or gets too blurry (ie a whip pan)
http://www.videocopilot.net/tutorials.html?id=92

thats the 2dish way

you can also use your 3d app (Maya, Max, Cinema etc) to track you a camera to import into AE