Prayas session cgi & cga by – soumalya nandy

Copyright © technoKrats

Tenet Systems Pvt. Ltd.An ISO 9001:2008 Certified Company

PrayasWednesday Work-out session – 22th July 2015

Presented By – Soumalya Nandy

CGI & CGA

Copyright © technoKratsCopyright © technoKrats 2

WHAT IS CGI TECHNOLOGY?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.


TYPES OF CGIComputer 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


TWO DIMENSIONAL IMAGERaster : 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.


TWO DIMENSIONAL IMAGE

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)


TWO DIMENSIONAL IMAGEVector : 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


TWO DIMENSIONAL IMAGEColor: 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).


Raster Vs. Vector


Geographic Information SystemGeographic 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.


Geographic Information System


Geographic Information SystemVector 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 IMAGEThree 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


THREE DIMENSIONAL IMAGE


TYPES OF CGAAnimation: 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.


CGA IN MIATURES 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.


THE SECRET OF MIATURES? 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.


THE SECRET OF MIATURES?

Video

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


HOW IT WORKSTo 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


CREATING CHARACTERS AND OBJECTS ON A COMPUTER

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


METHODS OF ANIMATING VIRTUAL CHARACTERS

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


TYPES OF CGAVFX : 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


BEHIND THE MAGIC The Visual Effects of -Transformers Age of Extinction

The Visual Effects of - The Avengers


HISTORY • 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.


HISTORY

• 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.


REALISM IN THE FUTURE• 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.


AcknowledgementI 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

Technology

twodimensional image

types of image

raster image vector

d computer graphics

raster graphics

image resolution

realtime computer graphics

raster images