The document discusses various post-production processes like editing, sound editing, visual effects, and compositing. It describes the differences between visual effects and special effects, with visual effects referring to digital post-production techniques while special effects involve on-set mechanical or optical techniques. The document also provides examples of different visual effects techniques like chroma keying, rotoscoping, wire and rig removal, camera tracking, and matchmoving.

1. B S Abhilash

2. 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.
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3. Visual fx Vs Special fx
 “Visual Effects" is referring to digital post-production
and "special effects" referring to on-set mechanical
effects and in-camera optical effects.
 Special effects are created during shooting, and Visual
effects are done in post.

4. Special Effects
 Mechanical effects
 Optical Effects

5. Mechanical Effects
 They are also called as practical or physical effects and
are usually accomplished during the live-action
shooting
 The use of
 mechanized props, scenery,
 scale models, Pyrotechnics
 Atmospheric Effects:
 creating physical wind,
 rain, fog, snow, clouds etc

6. Optical Effects
 Optical effects are done by manipulating the camera and
lighting which in turn will make your scene look different
than what it looks like to the naked eye.
 This could involve working with camera lenses, types of
lighting, or camera movements that give a certain look to
the shot.
 The special effects supervisor is in charge of making the
creative decisions and works directly with the director on
set to achieve what he/she wants.

7. VFX
 Visual effects may be divided into at least four categories:-
 Models: miniature sets and models, animatronics.
 Matte paintings and stills: digital or traditional paintings or
photographs which serve as background plates for keyed or
rotoscoped elements.
 Live-action effects: keying actors or models through bluescreening
and greenscreening.
 Digital animation: modeling, computer graphics lighting, texturing,
rigging, animating, and rendering computer-generated 3D
characters, particle effects, digital sets, backgrounds.
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8. Visual Effects
 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

9. Compositing
 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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10. Compositing
Compositing is taking real-life elements with Computer Generated (CG)
Element and putting them together - so they seem like they were shot
together. The viewer never suspects something is "not right".
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11. 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.
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12. VFX
 A visual effects supervisor is usually involved with the
production from an early stage to work closely with
production and the film's director to achieve the
desired effects.
 "visual effects" refer to digital post-production and
"special effects" refer to on-set mechanical effects and
in-camera optical effects.
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13. Chroma keying
 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.
 This technique is also referred to as
color keying, color-separation
overlay
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14. Chroma keying
 It is commonly used for weather
forecast broadcasts, wherein the
presenter appears to be standing in
front of a large map, but in the studio
it is actually a large blue or green
background.
 The meteorologist stands in front of a
blue screen, and then different
weather maps are added on those parts
in the image where the color is blue.

15. Chroma Keying
 If the meteorologist himself
wears blue clothes, his clothes
will become replaced with the
background video.
 This also works for
greenscreens, since blue and
green are considered the
colors least like skin tone
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16. Chroma Keying
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17. Chroma Keying
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18. Chroma Keying
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19. Rotoscoping
 Rotoscoping is an animation technique in which animators trace
over live-action film movement, frame by frame, for use in
animated films.
 Originally, pre-recorded live-action film images were projected
onto a frosted glass panel and re-drawn by an animator.
 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.
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20. Rotoscoping
The artist is drawing on a
transparent easel, onto which
the movie projector at the
right is throwing an image of
a single film frame.
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21. Rotoscopy

22. Rotoscopy

23. 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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24. Wire Removal
 Whenever you are trying to remove an item from a
shot, a background frame must be created for the area
covered by the offending item.
 This background frame with the item removed is
called the “clean plate.”
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25. Rig Removal
 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.
 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 – rig removal.
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26. Matchmove and Camera Tracking
 Camera tracking is the
process of matching the
movement of the CG
camera to the movement of
the camera used in the live-
action footage. As a result,
it is a crucial part of all
visual effects shots.
 Despite its importance, it is
completely invisible in the
final shot.
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27. 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.
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28. Matchmove and Camera Tracking
The camera tracking information lets you add 3-D animated
effects into live-action footage, such as:
 Animated 3-D character insertion (mascots, beasts, flying pixies,
you name it). A favorite for commercials.
 Vehicle insertion. Aircraft, boats, cars, trucks, spacecraft, things
you wish you could get live, but couldn't afford or don't exist.
 Architectural Pre visualization (ground level or helicopter)
 Virtual set extensions (boy, that's a fancy newsroom!)
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29. Resources
 http://www.hollywoodcamerawork.us/trackingplates.
html
 http://www.cgtantra.com/index.php?option=com_con
tent&task=view&id=267&Itemid=40