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# What is a 3D Computer Graphic?

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• Written By: G. Wiesen
• Edited By: Heather Bailey
2003-2018
Conjecture Corporation
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A 3D computer graphic is an image that uses computer software to create objects in virtual three-dimensional (3D) space. This is in contrast to two-dimensional (2D) images that exist only as flat images that may use visual tricks, such as perspective, to create the illusion of three-dimensionality. A 3D computer graphic is typically created by artists through the creation of a 3D model, consisting of a wireframe and polygons, which is then usually textured and lit before being rendered.

Often referred to simply as computer graphics (CG) or computer generated imagery (CGI), a 3D computer graphic is created using computer software that is developed specifically for creating 3D graphics. This type of imagery was originally created solely through mathematic algorithms and equations. Modern 3D imagery, however, is made through the use of software that presents a graphical user interface (GUI) to the artist, which allows a 3D computer graphic to be made without direct interaction between the artist and the mathematical properties of the image.

The creation of a 3D computer graphic typically begins with modeling the object that will appear in the final image. A cube, for example, can be created quite simply and, like all 3D imagery, consists of a wireframe and polygons. The wireframe is the basic shape of the object consisting of various points and the lines connecting those points. This can be easily imagined as what the object would look like if it was made out of chicken wire.

Polygons are the shapes, also called faces, which fill in the wireframe to create a solid 3D computer graphic. Using the example of a cube, the corners would be made of the points and lines of the wireframe, while the actual sides of the cube would be polygons or faces. This form is then textured, which means that images are applied to the polygons to provide it with an appearance beyond a single color. Such textures can include: simple graphics, such as an illustration of wood grain; bump mapping, which would provide a sense of depth to the creases in the grain; and reflection maps, which provide shininess to textures like glass and metal.

Once the object is modeled and textured, then lighting can be added to give the object shadows and highlights. This scene is then rendered to create a 3D computer graphic. During rendering, the various elements in the scene are composited and compiled to create an image file that can be used to share and view the 3D computer graphic scene. Many professional studios have groups of computers used only for rendering, as this process can take a long time and often requires a great deal of processing power.

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 Melonlity Post 3 @Logicfest -- hadn't seen the term "hardware geek" in a long time. Fortunately, it's usually a term of endearment! Anyway, all is not lost even if you don't have the best three-dimensional gaming card on the block in your computer. A lot of games allow the user the option to simplify the detail of graphics so games will run fine on graphics cards that aren't exactly state of the art. Still, a major advantage of game consoles is that picking one that will run the games you want to play is very easy. The same is not true if you want to do a lot of computer gaming. But there is a huge market for computer games and plenty of people (i.e., hardware geeks) who can tell you want you need to buy to have a good gaming rig. They tend to be friendly folks, so ask a few questions and you will do just fine. Logicfest Post 2 @Terrificli -- that's a tough question to answer. If you use a video game console for gaming, then it is a simple matter -- any modern console should handle three-dimensional graphics well and that has been true since the first of the 21st century. When it comes to computer gaming, you've got some work cut out for you. The main question to ask is how many polygons a graphics card can push around in a certain amount of time? High end graphics cards do a great job of that, while a lot of the graphics card built into motherboards simply do not. Read some reviews and ask some hardware geeks what to get an you will be OK. Terrificli Post 1 Those don't only take a lot of power to render -- a computer or gaming system has to have a lot under the hood to effectively process and display three-dimensional graphics. It can be very confusing to try to find the best hardware to render those graphics, particularly for people who like playing video games. What should someone look for if they want something that will render three-dimensional graphics for gaming?