Computer Graphics

Computer graphics (CG) is the field of visual computing, where one utilizes computers both to generate visual images synthetically and to integrate or alter visual and spatial information sampled from the real world. The first major advance in computer graphics was the development of Sketchpad in 1962 by Ivan Sutherland.

It is often thought that the first feature film to use computer graphics was 2001: A Space Odyssey (1968), which attempted to show how computers would be much more graphical in the future. However, all the "computer graphic" effects in that film were hand-drawn animation, and the special effects sequences were produced entirely with conventional optical and model effects.

Perhaps the first use of computer graphics specifically to illustrate computer graphics was in Futureworld (1976), which included an animation of a human face and hand--produced by Ed Catmull and Fred Parke at the University of Utah.

The first advance in computer graphics was in the use of CRTs. There are two approaches to 2D computer graphics: vector and raster graphics. Vector graphics stores precise geometric data, topology and style such as: coordinate positions of points, the connections between points (to form lines or paths), and the color, thickness, and possible fill of the shapes. Most vector graphic systems can also use primitives of standard shapes such as circles, rectangles, etc. In most cases, a vector graphic image has to be converted to a raster image to be viewed. Raster graphics is a uniform 2-dimensional grid of pixels. Each pixel has a specific value such as, for instance, brightness, color, transparency, or a combination of such values. A raster image has a finite resolution of a specific number of rows and columns. Standard computer displays shows a raster image of resolutions such as 1280(columns)x1024(rows) of pixels. Today, one often combines raster and vector graphics in compound file formats (pdf, swf).

With the birth of workstation computers (like LISP machines, paintbox computers and Silicon Graphics workstations) came 3D computer graphics, based on vector graphics. Instead of the computer storing information about points, lines, and curves on a 2-dimensional plane, the computer stores the location of points, lines, and, typically, faces (to construct a polygon) in 3-dimensional space. 3-dimensional polygons are the lifeblood of virtually all 3D computer graphics. As a result, most 3D graphics engines are based around storing points (single 3-dimensional coordinates), lines that connect those points together, faces defined by the lines, and then a sequence of faces to create 3D polygons. Modern-day computer graphics software goes far beyond just the simple storage of polygons in computer memory. Today's graphics are not only the product of massive collections of polygons into recognizable shapes, but they also result from techniques in shading, texturing, and rasterization.

Computer graphics is all about obtaining 2D images from 3D models. In order to get highly accurate and photo-realistic images, the input 3D models should be very accurate in terms of geometry and colors. Simulating the real 3D world scene using Computer Graphics is difficult, because obtaining accurate 3D geometry of the world is difficult. Instead of obtaining 3D models, image-based rendering (IBR) uses the images taken from particular view points and tries to obtain new images from other view points. Though the term "image-based rendering" was coined recently, it has been in practice since the inception of research in computer vision. In 1996, two image-based rendering techniques were presented in SIGGRAPH: light field rendering and Lumigraph rendering. These techniques received special attention in the research community. Since then, many representations for IBR were proposed. One popular method is view-dependent texture mapping, an IBR technique from University of Southern California. Andrew Zisserman, et. al from Oxford University used machine learning concepts for IBR.

Flat shading: A technique that shades each polygon of an object based on the polygon's "normal" and the position and intensity of a light source.
Gouraud shading: Invented by Henri Gouraud in 1971, a fast and resource-conscious technique used to simulate smoothly shaded surfaces by interpolating vertex colors across a polygon's surface.
Texture mapping: A technique for simulating surface detail by mapping images (textures) onto polygons.
Phong shading: Invented by Bui Tuong Phong, a smooth shading technique that approximates curved-surface lighting by interpolating the vertex normals of a polygon across the surface; the lighting model includes glossy reflection with a controllable level of gloss.
Bump mapping: Invented by Jim Blinn, a normal-perturbation technique used to simulate bumpy or wrinkled surfaces.
Normal mapping: Related to bump mapping, a more in-depth way of simulating bumps, wrinkles, or other intricate details into low-polygon models.
Ray tracing: A method based on the physical principles of geometric optics that can simulate multiple reflections and transparency.
Radiosity: a technique for global illumination that uses radiative transfer theory to simulate indirect (reflected) illumination in scenes with diffuse surfaces.
Blobs: a technique for representing surfaces without specifying a hard boundary representation, usually implemented as a procedural surface like a Van der Waals equipotential (in chemistry). [source: Wikipedia]

Links to Computer Graphics

www.iCLIPART.com : iCLIPART.com offers the highest quality collection of clip art available on the Internet. Plus they have the largest QUANTITY of any clipart site with over 6.2 million images. The vast majority of their content is provided in vector file formats (.EPS & .AI) making it the perfect choice for home, hobby, school and professional users. iCLIPART.com gives you all the graphics you’ll ever need to make your design projects POP - Unlimited Access to Over 6.2 Million Images - Massive Array of Styles and Categories - Multiple File Formats - WIN/MAC - Professional Quality - No Per-Image Fees

PhotoPost: PhotoPost PHP is a fast, MySQL powered fully customizable community photo gallery application that allows you and your site's users to upload photos to galleries and post forum style comments and ratings for those photos. PhotoPost supports both images and multimedia files, plus multiple file uploads via ZIP files or FTP with auto thumbnail generation, and includes a full featured user registration system with usergroup editing to set diskspace and gallery access privledges.

The GIMP Homepage: The GIMP is the GNU Image Manipulation Program. It is a freely distributed piece of software suitable for such tasks as photo retouching, image composition and image authoring. This site contains information about downloading, installing, using, and enhancing GIMP. This site also serves as a distribution point for the latest releases, patches, plugins, and scripts. We also try to provide as much information about the GIMP community and related projects as possible.

Cooltext.com : Cooltext.com is an online graphics generator for web pages and anywhere else you might need an impressive logo without a lot of work. We provides real-time generation of graphics customized exactly the way you want them. Simply choose what kind of image you would like to create. Then, fill out a form and you'll have your own images created on the fly. Cooltext.com will always be available for use free of charge.

Graphics by Pat: The graphics on this web site are linkware and free for you to place on your personal non-commercial web sites if you follow some simple guidelines As long as you do not alter the graphics from its original form you may use my graphics. This means you can't change the coloring or the content, you may only resize it. And please drop me a line sending me the graphic so I can see what you have done.

FreeGraphics.com : Contains a huge list of websites on free graphics rated according to their merit. Get Buttons, bars, sets, clip art, and a lot of things you'd have never thought of. Yes, these sites all have free graphics (you pay no money), but some do have usage restrictions such as requiring a link back to their site and different restrictions for personal vs. commercial use. Be sure to read the usage requirements at each site as they vary greatly.

ABCGiant.com : Get Fonts, Backgrounds, Buttons, 3D Balls, 3D Bullets, Arrows, Banners, Online Tools and Barlines. Over 8,000 images to choose from. The site uses pop ups.

Free- Graphics.com: That's right, you've arrived at All Free Original Clipart. Now Hosting Over 30,000 Free Clipart Images, such as animated gifs, icons, backgrounds, bullets, clip art, and pictures; all free for you to download. Browse the many pages on this site, or, follow one of the countless number of great links that will take you to other sites. This is your number one source for finding free clipart. This site contains a lot of free clipart, you can't see everything in just one visit.

CoolGraphics.com: Animations Arrows Backgrounds Bullets Buttons Clipart Counter Digits Lines all for free.

Animation Central: Home of the Internet's best clipart, animation, and web graphics. This site is filled with more than 12,000 high quality, free graphics! We don't call this masterpiece the "Site of The Week" for nothing. So what are you waiting around for ? Why not check it out now?

Animation Factory - Free Animated GIFs and 3D Clipart: Easy to use animations to decorate your email, web pages, and PowerPoint™ presentations. Click on a category to the left to browse our 3,000 free animated GIF samples. Become a member of Animation Factory and get over 200,000 original animations and graphics. New images added every month!

ProDraw Graphics : ProDraw Cartoon Clips Library. The best graphics resource to add spice to your web pages and documentation. With a 5-Star Rating from ZDNet. In fact, it's not necessary to say more about our clipart

FlamingText.com: At this site you can create cool, custom images for FREE, to use on your website, or in your e-mail. FlamingText.com is committed to providing you with the best and easiest to use graphic resources on the net. Our strongest ability is development. We are extremely knowledgeable in C and Java, and have good knowledge of Perl and all things web.

Rad-gfs.com Radical website graphics : Backgrounds Animations Oval Buttons Small Medium Large Square Buttons Small Medium Large 3d Balls Small Medium Large New Graphics! Links Fonts Bullets Circle Buttons Small Medium Large Numbers Small Medium Large Banners Small Medium Large Webmaster Tools

GraphXKingdom : Welcome to Graphxkingdom. The Graphxkingdom is home to thousands of clipart, icons, backgrounds, bars, interfaces, and other cool, free graphics.

Absolute Web Graphics : ONE OF THE LARGEST COLLECTIONS OF FREE WEB GRAPHICS ON THE INTERNET Now with 10000 arrows, lines, bullets, buttons, balls, clipart and icons for use in web pages or desktop publishing. Graphics found on this site were not created by the webmaster. They were obtained from various sources on the internet that labeled them as "freely distributable".

WebPage Design.com: Welcome to Art for the web. The free stuff includes: Templates, Interfaces, Backgrounds and Flash animations.

Graphics- 4Free: Your source for free custom made buttons, bullets, dividers and other quality graphics.

Animation Library : Welcome to the NEW Animation Library, a site featuring over 13,754 free animations for you to use on your website or send as digital postcards using our powerful Postcard Station. While you browsing the Animation Library, you can listen to great music by using the Jukebox. This site uses many pop up ads. If you are comfortable with them, you can take advantage of the free graphics.