How to go about green screen removal of leg?

[Omnidecay]

Yes and no;
Yes- You can just chroma out someones limbs providing you have a back ground for them. If you were to just key it out, black would be the only thing left.

No-They used multiple programs to do these effects, AE alone is not going to give you the look you want. It will remove the limb, but it will look odd. Not to mention, whatever type of camera your working with. Major bleeding will be a problem if not lit 100% correctly. Its a good starting point, but more often then not 3d programs are used to clean things up (nub of the limb).

[Josh J. johnson]

Thanks for the reply what would be my bg plate for the keying of the leg? What I just have to have the same shot except shoot it without my actor then use that? Or is thier some sort of coping or cloneing process I could do in AE.

thanks

[Majorasshole]

you will have to have a locked down camera for every shot, and nothing can get between the camera and the limb. If you dont wan’t the camera to move then just shoot the environment without anyone in it. If you want to move the camera you will need a motion control camera to capture a clean plate with the camera movement. In both cases you will have to also rotomask the shadow of the leg out of the scene. It is not plug and play, it will take some compositing creativity.

[Brendan Coots]

It depends on the background you are using. If it’s a very simple, solid background you can probably get away with a cloning approach, but more than likely you will need to manually work it over to get a good result.

A clean BG plate would be very helpful provided it’s a locked off camera. That said, unless you have access to a lot of crazy high-end gear and you know how to use it all, I wouldn’t even think about doing anything BUT a locked off shot for this type of thing.

As was mentioned upstream, you will need some way to “cap off” the legs where the greenscreen ends and their flesh begins. This is usually done in 3D, but would also require you to motion track your shots and pull that data into your 3D package in order to properly line up the 3D “nubs” to the actor’s appendages.

No matter how you slice it, it’s not an easy process.

[Delete]

You don’t have to have it locked down to in the shots. You also don’t have to have it green wrapped unless you want. One way or another you’re going to end up with doing some rotoscoping. Use a background plate of the location and track it to the movement of your foreground plate. Andrew Kramer is really the person to ask about this stuff.

[Jason Sanders]

check out this tutorial by Andrew Kramer
https://www.videocopilot.net/videotutorials/suicide/
this might be what you want, or at least get you started.
Good luck!

Jason Sanders
http://www.hecticfilms.com

[Josh J. johnson]

Thanks guys!

[Chris Forrester]

Just as a side note, be sure to keep an eye on any cast shadows. You will want to also remove that part of the leg also if it is visible. If your not using any motion ccontrol shots it just means painting/cloning in more background which “can” be a real pain in the butt…even more so now you have cast shadows to think about!

Regards

~Chris

[Majorasshole]

here is a bit of info from how they did this effect to Gary Sinise in Forrest Gump with a really bad photograph.
https://www.time.com/time/photogallery/0,29307,1622338_1363003,00.html

https://sinisefans.org/gump/fx3.jpg

[Majorasshole]

oops wrong link
https://www.sinisefans.org/gump/gumpfx.html