VFX
Post-production
Post-production is, in fact, many different processes grouped under one name. These typically include:-
Editing the picture / television program
Writing, (re-)recording, and editing the soundtrack.
Adding visual special effects - mainly computer-generated imagery (CGI) and digital copy from which release prints will be made (although this may be made obsolete by digital-cinema technologies).
Transfer of film to Video or Data with a telecine and Color grading. 2
VFX
Visual effects (commonly shortened to Visual F/X or VFX) are the various processes by which imagery is created and/or manipulated outside the context of a live action shoot.
Visual effects often involve the integration of live-action footage and computer generated imagery (CGI) in order to create environments which look realistic, but would be dangerous, costly, or simply impossible to capture on film.
They have become increasingly common in big-budget films, and have also recently become accessible to the amateur filmmaker with the introduction of affordable animation and compositing software. 3
Visual Effects methods
Rotoscopy
Rig and Wire Removal
Camera Tracking and Match Moving
Green and Blue Screen & 3D elements to interact with live action
Color Correction
Matte Painting
Compositing
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It is the combining of visual elements from separate sources into single image, often to create the illusion that all those elements are parts of the same scene
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Chroma keying ď ľ
Chroma key compositing (or chroma keying) is a technique for mixing two images or frames together in which a color (or a small color range) from one image is removed (or made transparent), revealing another image behind it.
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This technique is also referred to as color keying, color-separation overlay
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Rotoscoping ď ľ
Rotoscoping is an animation technique in which animators trace over live-action film movement, frame by frame, for use in animated films.
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Originally, pre-recorded live-action film images were projected onto a frosted glass panel and re-drawn by an animator.
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This projection equipment is called a rotoscope, although this device has been replaced by computers in recent years. In the visual effects industry, the term rotoscoping refers to the technique of manually creating a matte for an element on a live-action plate so it may be composited over another background. 7
Wire Removal
In an action movie there can be literally hundreds of wire removal shots. A production technique called a “wire gag” is used where the talent is rigged up with wires to either assist him to leap over a tall building with a single bound or as a safety feature to save him from certain death.
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Rig Removal ď ľ
A close cousin of wire removal is rig removal. A rig is any kind of device used on the set to hold up an item up for filming.
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After the rig has done its job, it must then be removed from the scene. It is usually rigid like a rod or pole.
The city fathers were unwilling to cut the light down and the director simply had to have this particular camera position to get his shot. The solution –9 rig removal.
Matchmove and Camera Tracking
If CG elements (the crow in this case) interacts with objects which are a part of the footage (the branch of a tree), then matchmoving is needed for that object or character.
The CG model of that object or character needs to replicate the movement of the actual object or character.
This is important as it can be used to cast shadows, receive reflection, and is also a very good base for animators to plan out their animation. 10
VFX Softwares