Module 2 : Matchmove/Tracking_3 EN

Creating the illusion: final image assembly

Compositing

Compositing is the final stage in finalising a film. This is where the elements rendered by the lighting and created by the FX and environments are integrated into the final image. Imagine a hamburger: the bun, the burger, the tomato slices... and the sauce.Well, it's the same thing: you assemble all the elements in layers to make up the final image, and above all you add the sauce that makes it all work: the final camera effects (distortion, depth of field, glow, chromatic aberration, defocus...), the colour correction of the shot, the transition requirements. This stage is both artistic and technical.You can view a video of an example here .

As it is the last link in the chain, compositing is often where last-minute feedback from the director or producer (a little but more blue... no, redder...) comes in.The compositor has to be extremely adaptable, because sometimes an image has to be drastically modified using whatever means are available. Compositing also often involves mixing several videos together.

For example, we might film a static car in front of a green background, then remove the green background and add another video of a moving set, simulating the movement of the car.Even if there’s no plate (filmed image), there is still a need for compositing, because there are a whole range of compositing techniques for improving a full CG image, making it realistic or, on the contrary, stylising it.

Paint & Prep

Compositing

Sometimes there's no CG to integrate, no environment, no FX, and yet there's still compositing to be done.You need to remove a pole that’s been left in the frame, remove an actor who shouldn't be there, a pimple on a face.This is also the role of compositing, but in some studios there is a department dedicated to this, called Paint and Prep.The term prep is used because the plan is being prepared for its future or final use.

Removal of markers and marker wiresSource : visual effects workshops

Rotoscopy

Compositing

Compositing also involves the sometimes thankless task of rotoscoping. This is the action of cutting out certain elements frame by frame to extract them from a plate.Although artificial intelligence has made progress in this area, it's still not perfect, and roto often remains the gateway for any aspiring compositor.

Examples of rotoscopySource : foundry.com

Software used: the industry's flagship software is Nuke. It's the most widely used, but some people use After Effects, which is also very effective for motion design. Flame is sometimes used in advertising.Also, because it's free, some people use Fusion, and Blender's compositing interface. From the green screen to the integration of 3D, not forgetting all the possible video retouching, compositing is the Swiss army knife of VFX.See an article here entitled "SmartROTO: enabling rotoscoping with artist-assisted machine learning".