Prayas session cgi & cga by – soumalya nandy

Copyright © technoKrats
Tenet Systems Pvt. Ltd.
An ISO 9001:2008 Certified Company
Wednesday Work-out session – 22th July 2015
Presented By – Soumalya Nandy

Copyright © technoKratsCopyright © technoKrats 2
Computer graphics is responsible for displaying art and image data effectively and
beautifully to the user, and processing image data received from the physical
world. The interaction and understanding of computers and interpretation of data
has been made easier because of computer graphics. It have had a profound
impact on many types of media and have revolutionized animation, movies and
the video game industry.
Computer-generated imagery (CGI) is the application of computer graphics to
create or contribute to images in art, printed media, video games, films, television
programs, commercials, videos, and simulators. The visual scenes may be dynamic
or static, and may be two-dimensional (2D), though the term "CGI" is most
commonly used to refer to 3D computer graphics used for creating scenes or
special effects in films and television.
Video games most often use real-time computer graphics (rarely referred to as
CGI), but may also include pre-rendered "cut scenes" and intro movies that would
be typical CGI applications.

Computer generated imagery(CGI) can be categorized into two types:
 Two-dimensional
 Three dimensional
Computer generated imagery(CGA) can be categorized into two types:
 Animation
 VFX
Two-dimensional : The computer-based generation of digital images (also
called raster graphics) — mostly from two-dimensional models such as geometric
models (also called vector graphics), text and by techniques specific to them. They
mainly used in the specific type of applications that were originally developed upon
traditional printing and drawing technologies, like typography, cartography, technical
drawing, advertising, etc. In those applications, the two-dimensional image is not
just a representation of a real-world object, but an independent artifact with added
semantic value.
Depending on whether the image resolution is fixed, it may be following types:
• Raster image
• Vector image

Raster : Raster images have a finite set of digital values, which is called the picture
elements or pixels. The digital image contains a fixed number of rows and columns of
pixels. Pixels are the smallest individual element in an image, holding quantized values
that represent the brightness of a given color at any specific point.
Typically the pixels are store in
computer memory as a 2D array
of small integers. This types of
image created by digital camera
or scanner.
Color : Scanner images using 24 bit (16 million color) . Other images may use 8 bit(256
colors).
Resolution : It is defined by dos per inch(dpi).If you have 300 dpi image and increase
the size, typically the edges and lines will become jagged. As a result the ‘squares’ i.e.
pixels, get bigger.

Size: Since raster images are composed of color pixels, the graphics program must
keep track of all the information relevant(all colors, specific location of each pixel
etc.) to the image. So larger the image and more colors used-the larger the file size.
Files: the most commonly used formats are:
• BMP(Bitmap)
• TIFF(Tag Inter Leave Format)
• JPEG (Joint Photographic Expert Group)
• GIF(Graphics Interchange Format)
• PNG(Portable Network Graphics)
• PSD(Adobe Photoshop)

Vector : It consists of individual points, which (for 2D data) are stored as pairs of (x, y)
co-ordinates. The points may be joined in a particular order to create lines, or joined
into closed rings to create polygons, but all vector data fundamentally consists of lists
of co-ordinates that define vertices, together with rules to determine whether and
how those vertices are joined.
Original photo vector art

Color: color gradient is used for a gradual blend of color. In computer graphics, a
color gradient (sometimes called a color ramp or color progression) specifies a
range of position-dependent colors, usually used to fill a region. The colors
produced by a gradient vary continuously with position, producing smooth color
transitions.
Resolution: As ratio in math images can be ‘scaled’ up or down with out loosing
any integrity to the quality-they are the most popular graphics format for clip art
and for transferring to printed materials.
Files: the most commonly used formats are:
• EPS(Encapsulated Post Script)
• WMF(Windows Meta File)
• AI(Adobe Illustrator)
• DXF(Auto CAD)
• SVG(Scalable Vector Graphics)
Size: Do not need to keep track of each pixel but rather only the mathematical
information. So files are relatively small in size(file size will be same for a 3 inch
image and for a 3 foot by 3 foot image).

Geographic Information Systems (GIS) is an
integrated collection of computer software
and data used to view and manage
information about geographic features, such
as cities, buildings, roads, and water. GIS
provides a framework for gathering and
organizing spatial (geographic) data and
relating information so that it can be
displayed, inventoried, and analyzed.
GIS can be used to map quantities and
densities to show population rates over a
city, county, state, or nation. GIS is often
confused with GPS or Global Positioning
System. GPS technology uses the position
of satellites to determine desired locations
on the earth. Today GIS and GPS are used
together to effectively map locations and
features on the earth.

Vector data model: A representation of the world using points, lines, and
polygons. Vector models are useful for storing data that has discrete boundaries,
such as country borders, land parcels, and streets.
Raster data model: A representation of the world as a surface divided into a
regular grid of cells. Raster models are useful for storing data that varies
continuously, as in an aerial photograph, a satellite image, a surface of chemical
concentrations, or an elevation surface.

Three dimensional : 3D computer graphics rely on many of the same algorithms as
2D computer vector graphics in the wire-frame model and 2D computer raster
graphics in the final rendered display. 3D computer graphics are often referred to
as 3D models. Apart from the rendered graphic, the model is contained within the
graphical data file. However, there are differences. A 3D model is the mathematical
representation of any three-dimensional object. A model is not technically a
graphic until it is displayed. A model can be displayed visually as a two-dimensional
image through a process called 3D rendering, or used in non-graphical computer
simulations and calculations.
3D computer graphics creation falls into three basic phases:
• 3D modeling – the process of forming a computer model of an object's
shape
• Layout and animation – the motion and placement of objects within a
scene
• 3D rendering – the computer calculations that, based on light placement,
surface types, and other qualities, generate the image

Animation: Computer animation, or CGI animation, is the process used for
generating animated images by using computer graphics. The more general term
computer-generated imagery encompasses both static scenes and dynamic images
while computer animation only refers to moving images.
Modern computer animation usually uses 3D computer graphics, although
2D computer graphics are still used.
Computer-generated animations are
more controllable than other more
physically based processes, such as
constructing miniatures for effects
shots or hiring extras for crowd
scenes.

In a world where CGI seems to always be the first choice…models and miniatures
offer realism and immediate feedback in-camera to let you know if you got the shot.
Steven Spielberg used a model ship in the Mojave Desert of California to double for
the Gobi Desert of Mongolia. By placing it close to the camera and using a wide lens
with deep-focus…he sold the size and scale of an impossible scenario that visually
awed the audience.
20-foot long
model with
actors 1/4 mile
away.

Vashi Nedomansky - ‘The Grind’is a crime drama(demo miniature).
What we needed was a Humvee miniature for a flashback scene that occurs in a
desert during the First Iraq War.
We needed was a
Humvee miniature for a
flashback scene that
occurs in a desert during
the First Iraq War.

Video
The Humvee was about 2 feet from the camera and the actors were 40 feet
away.

To trick the eye and brain into thinking they are seeing a smoothly moving
object, the pictures should be drawn at around 12 frames per second (frame/s)
or faster (a frame is one complete image). With rates above 75-120 frames/s no
improvement in realism or smoothness is perceivable due to the way the eye
and brain process images. At rates below 12 frame/s most people can detect
jerkiness associated with the drawing of new images which detracts from the
illusion of realistic movement. Conventional hand-drawn cartoon animation
often uses 15 frames/s in order to save on the number of drawings needed, but
this is usually accepted because of the stylized nature of cartoons. Because it
produces more realistic imagery, computer animation demands higher frame
rates to reinforce this realism.
Movie film seen in theaters runs at 24 frames per second, which is sufficient to
create the illusion of continuous movement. For high resolution, adapters are
used.
VIDEO IMAGE

3D computer animation combines 3D models of objects and programmed or
hand "key framed" movement. These models are constructed out of geometrical
vertices, faces, and edges in a 3D coordinate system. Objects are sculpted much
like real clay or plaster, working from general forms to specific details with
various sculpting tools. Unless a 3D model is intended to be a solid color, it must
be painted with "textures" for realism. A bone/joint animation system is set up
to deform the CGI model (e.g., to make a humanoid model walk). In a process
known as rigging, the virtual marionette is given various controllers and handles
for controlling movement. Animation data can be created using motion capture,
or key framing by a human animator, or a combination of the two. IMAGE

In most 3D computer animation systems, an animator creates a simplified
representation of a character's anatomy, which is analogous to a skeleton or
stick figure. The position of each segment of the skeletal model is defined by
animation variables, or Avars for short.
There are several methods for generating the Avar values to obtain realistic
motion. Traditionally, animators manipulate the Avars directly. Rather than set
Avars for every frame, they usually set Avars at strategic points (frames) in time
and let the computer interpolate or tween between them in a process called
key framing. Key framing puts control in the hands of the animator and has
roots in hand-drawn traditional animation.
In contrast, a newer method called motion capture makes use of live action
footage. When computer animation is driven by motion capture, a real
performer acts out the scene as if they were the character to be animated.
His/her motion is recorded to a computer using video cameras and markers
and that performance is then applied to the animated character. Video

VFX : In filmmaking, visual effects (abbreviated VFX) are the processes by which
imagery is created and/or manipulated outside the context of a live action shot.
Visual effects involve the integration of live-action footage and generated imagery
to create environments which look realistic, but would be dangerous, expensive,
impractical, or simply impossible to capture on film.
VIDEO

The Visual Effects of -Transformers Age of Extinction
The Visual Effects of - The Avengers

• Early digital computer animation was developed at Bell Telephone
Laboratories in the 1960s .
• 2D CGI was first used in movies in 1973's Westworld, though the first use of
3D imagery was in its sequel, Futureworld (1976).
• In 1995, the first fully computer-generated feature film, Pixar's Toy Story, was
a resounding commercial success.
• Additional digital animation studios such as Blue Sky Studios (Fox) and Pacific
Data Images (Dreamworks SKG) went into production, and existing animation
companies such as Disney began to make a transition from traditional
animation to CGI.

• Between 1995 and 2005 the average effects budget for a wide-release
feature film skyrocketed from $5 million to $40 million. According to one
studio executive, as of 2005, more than half of feature films have significant
effects.
• Developments in CGI technologies are reported each year at SIGGRAPH, an
annual conference on computer graphics and interactive techniques that is
attended by thousands of computer professionals each year. Developers of
computer games and 3D video cards strive to achieve the same visual quality
on personal computers in real-time as is possible for CGI films and animation.
Video
• Computer animation helped to create blockbuster films, such as Toy Story 3 ,
Shrek 2 (2004), (2010), Avatar (2009), Cars 2 (2011), Life of Pi (2012), and
Frozen (2013), Fast & Furious 6(2014), Jurassic World(2015), Furious 7(2015)
etc.

• One of the greatest challenges in computer animation has been creating
human characters that look and move with the highest degree of realism.
•Part of the difficulty in making pleasing, realistic human characters is the
uncanny valley, the concept where (up to a point) the human audience tends to
have an increasingly negative emotional response as a human replica looks and
acts more and more human.

I would like to thanks management for giving me the opportunity to present my view
through the Prayas session. I am thankful to my mentor Mr. Joydrit Goswami and
other co-worker for supporting me. I have collected all the data from following:

Copyright © technoKrats
Thank you for your time!
technoKrats
43, N K Guin Lane, Serampore,
Hooghly – 712201, India.
Call: +919830158077 or
+1-850-745-0414
Web: http://technokrats.in
Tenet Systems Pvt. Ltd.
42, N K Guin Lane, Serampore,
Hooghly – 712201, India.
Call: +919830158077 or
+1-850-745-0414
Web: http://tenetsystems.net

Prayas session cgi & cga by – soumalya nandy

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Prayas session cgi & cga by – soumalya nandy