Matchmoving a video background of an ACTUAL Building to ACTUAL Actors on greenscreen

Hi guys and thank you for reading this.

I have a little script that calls for the actors to run arount the top of a building and then to jump from that building to the street. I have FCP 7, Motion, A greenscreen Cyc in my backhouse and a friend that will shoot the actual building backplate footage.

1)What's the best keyer for this?

2)Best (least expensive) matchmoving software?

3)Any examples on youtube (can't find any that will match an ACTUAL BUILDING or BACKGROUND with ACTUAL ACTORS it's always a combination of CGI Buildings and Actors)

4) any thoughts or pointers is this even possible?

Thank you for your kindness and respectful non sarcastic responses!

Pablo

I wonder if you could do something with pinning to acheive this? Track a point on the building and match that to a point on your green version.

Optimally there would be a rig set up to make the camera perform the exact same action twice. If you could do that you'd be sweet. You problem is going be the inconsistencies between the two camera moves and frame sizes.

Does the camera really have to track? It's going to be way easier to achieve with static frames.

Thanks Jude I guess I could get away with static frames

Best matchmoving software is Mocha. There's a learing curve involved, but once you get into it, it's excellent. If you have or have access to After Effects, the basic version is already there. Upgrade to Pro for something like what you're talking about.

[www.imagineersystems.com]

>(can't find any that will match an ACTUAL BUILDING or BACKGROUND with ACTUAL ACTORS it's always
>a combination of CGI Buildings and Actors)

There's a reason for that. Video is 3D captured in a rasterized 2D image. It's about having things in 2D space and trying to achieve 3D movement (depth). Let's say you have a cube, or rather, a building, and you shoot it at a 90 degree angle and you roto out the building. All you see is a square (or rectangle) because it is rasterized 2D. Now, let's say you shot a crane up over a field, and you want to plant your building (or your subject) on the field, so the shot tilts up and reveals the top of the building. The camera now has to move in that manner over your subject. Which is impossible, because all you have is a rectangular object in 2D, and you don't have the angle from the top of the building.

The only way you can get it done without getting into 3D space is to have a mechanical crane and you shoot the object in the same arc and speed that you are using when you shooting your background plate. The best place to do it is in a controlled environment. But what's even better if you have live subjects, is to use Mocap and 3D models.

There are ways to cheat this, but some of it comes down to limitation due to actual physics- and you just don't have the data to create a 3D image of your subject to manipulate it in 3D space. So yea, some movements are impossible.

If you are talking about tracking and putting a signboard onto a bus, or replacing an object (like a trash can) in a panning shot, or a person, that is possible with tracking and a bit of roto. Just make sure you plan your shoot properly.

You can track and roto in Motion if you have a lot of patience and you know how to use groups. Or Mocha or AE or Nuke... AE has better keyers than the built in keyer in Motion, and Nuke has even better keyers.



www.strypesinpost.com