I'm about to start a small compsiting project and i would like to know if...

Is is possible to add a background animation and “take out” the foreground of the (people and such), if so how could i achieve this, i know how to Rotoscope and stuff like for instance, i’m adding lightsabers to a movie right now.

Thanks in advance.:spin:

Depends on the stuff you have to erase. You can mask the people out but then you will have to have something to fill in in their place. This could mean you have to fill in the areas frame by frame. Quite laberous if you do not have a uniform background.

Wouldn’t you normally shoot the subjects (people, etc.) against a green screen?

Also remember to shoot “background plates”. This way, once you have masked/roto the people out, you have a clean background to put them against.

Say i did this against a green/blue screen, what would i do next?

Bring your video into Blender through a compositor Image node. Pipe that through a Chroma Key node and insert your background of choice.

Here’s a tutorial (not mine) on green screening in Blender:

and make sure your greenscreen is evenly lit and not made out of bad plywood. Those suck!!

Ahem… The reason those suck is because between the shadows and the plywood texture bleeding through the paint you get a background that is NOT an even shade of green. Without that you will get artifacts in your chromakey as the areas that dont match dont get keyed out.