Place chroma-keyed actor inside inside Cinema 4d object

[Pixelproducer]

Hi there,

I have a clip of an actor which is standing in front of a green screen. So after I removed the background, I wanted to add this clip inside a 3d object.

To be more specific, I have a 3d model of a ship on which I wanted to place him.

How can I add him to the scene, so that there are some parts of the ship in front of him and some in the background, but the ship is one Cinema 4d object?

Thanks for your help!

[Dave_LaRonde · Accepted solution]

It's pretty easy, actually:  you have to think of your C4D object as 2D layers.  On the bottom layer, the C4D object .  On the middle layer, the chroma-eyed subject.  On the top layer, the C4D object again.  Through the use of masks, perhaps animated, you can make the subject look like it's within the 3D animation.

There may be other things necessary: parenting, motion tracking... we just don't know

[Rick Gerard]

It's pretty easy to create the mattes you need by using 2 instances of the C4D object, you just include the foreground elements in the top copy and put that file above the live footage. This usually requires making 2 copies of the model, one with only the foreground elements. Then, providing your tracking, scale, camera position and all of the other technical aspects of creating a composite are OK, it will look like your actor is actually inside the set. Getting the actor in between the foreground and background is the easy part. Making it look real is the hard part and that requires very careful pre-production planning and some great camera work.

If you render from C4D you can also generate mattes using the multi pass rendering options but that's another discussion.