There are many elements involved in VFX and post-production, but perhaps one of the most important roles in a VFX team is that of the compositor.
VFX compositors are the skilled professionals who bring together the visual effects with the live footage, ensuring that the audience can’t tell where one ends and the other begins.
Now, we’ve all seen examples, particularly in some older examples of VFX use, where it’s painfully obvious where the effects have been layered onto footage shot with real actors. But the key is to make the VFX almost invisible.
By which we mean that it blends so seamlessly with the rest of the footage that you don’t realise it’s been added at all.
What steps are involved in VFX compositing?
Compositing isn’t as simple as layering one piece of footage over another, or adding the VFX to your live footage, although this is where a compositor will start. But there are a number of additional steps required to make that into a polished final video.
These include colour correction to ensure that the VFX that are added look as though they were in the real scene and what are called Z-depth adjustments.
This means calculating the depth and distance of an object that is artificially added to the scene to ensure it is the right size and casts the right shadow or has the right lighting.
VFX compositing can also involve 3D modelling to create objects or even characters that weren’t in the scene when it was shot.
When is VFX compositing introduced to the post-production process?
VFX compositing is usually one of the later stages of post-production, because the compositor needs all the other elements of the scene to be ready before they can do their job.
The compositor’s role is to make the scene look as realistic as possible and ensure that all the aspects that are included blend seamlessly together to create one compelling scene.
When might you use VFX compositing?
Many video production projects will use at least some form of VFX compositing these days. However, one of the most common uses of VFX compositing is when a scene is shot in front of a green screen with a background layered behind.
Given the cost of shooting on location when you consider not only the travel expenses but also likely accommodation for all of your crew, it is often much more cost effective to use a green screen.
This is particularly the case if you only need a short piece of footage – such as for an advert.
Rather than travelling to the mountains in Europe, for instance, you could hire a green screen studio, shoot the actor performing the action you want to capture (like running) and then add the mountain scenery with VFX post production.
This is where your compositor would play a crucial role, because they would adjust the scenery and lighting in the footage to make it look as though the actor really was running along a mountain trail, when the reality may be that they were running in a studio in Manchester.