How do they mix real characters with animated characters?

Question

Some animated movies show real characters (men/women) in them like in the movie Avatar (2009). How do they mix real characters with animated characters? Does it cost more than a purely animated movie? What is the shooting/filming process to achieve it? Which technologies are used?

Answer 1

The process is called Digital Compositing, which is done using (After Effects, Nuke, or Photoshop).Firstly, you need to know shoot the footage and at the same time have something in the scene for the actor to react with. After filming we would make sure we know the camera aperture (camera specs) so me can 3D track the scene using one of the many 3D camera tracking software (Auto Desk Matchmove(free) After Effects, Nuke, Boujou)

after the camera is tracked you'll place the character in your 3D application of choice (Maya, 3Ds max, Cinema 3D, Blender) the list goes on.

After all that's said and done you'll render out your objects using your favorite render package (VRay,Arnold,Iray,Mental-Ray.) You have the option to render out Passes. Which is a different file for everything weather it's the Lights,Shadows,Reflection or even the dept. This list goes on and on and on.

You'll then add all the files (jpeg,png,tga) into your compositing application then put them all together and you'll get Avatar.

That's the short version of it. I hope this helps.

Answer 2

In modern movies the process for CGI is VERY expensive. Everything is shot on the same cameras as all other movies the only thing different in the process is what the actors have to do. To give an example of a current movie, within Infinity War they had a man equipped with a cardboard cutout of Thanos (where his eye level would be) So the actors knew where to look. The same goes for most other films, they have an item that is a representation of the CGI Character.

As for the Process... The difference is that the lighting crew for the CGI needs to render out the right lighting for the characters in the movie. There is also the final adjustments in the final compiling where they are layering the CGI over the film and making it look like they are actually there. Movie magic they call it.

Overall it is a lot more work to do that, but the effect it has on the audience is just as great, so in the end it is worth it.

It is a lot of money to make a full 3D movie as well, since the process for creating a 3D animated character is a lot of work and you have to do it for every character in the movie, some can be more limited than the others depending on how they are used.

If you want to learn more about Animation and these processes i am more than willing to help explain more, there's just so much to explain.