Page 113 - DCAP504_Computer Graphics

Computer Graphics

The 3-D rendering process is implemented to display a model as 2-D image. The 3-D rendering process
can also be used in fields that are not related to graphics like simulation. 3-D modeling deals with the
creation of geometrical data for 3-D computer graphics.

Table 8.1 : Difference between 2-D and 3-D Technique

2-D Technique 3-D Technique
It is two-dimensional representation. It is three-dimensional representation.
Virtual third dimension can be created which Third dimension is real, not virtual.
is static.
Includes typography, cartography, and Similar to photography and sculpting.
advertising. Similar to painting.
A 2-D shape A 3-D shape

8.1 3-D Representations

A three-dimensional model displays an item or picture in such a way that it appears to be physically
present on the screen of a computer. The item on the screen that appears flat (2-D item) to the human
eye is displayed with dimensions that include height, width and depth.
3-D items are represented with the aid of digital computers and 3-D software. The two main
Application Programming Interfaces (APIs) used for generating images are Open GL and Direct3-D.
The creation of 3-D graphics can be divided into stages such as content creation, scene layout and
rendering.
Content Creation

Content creation stage involves activities such as 3-D modeling, texturing and animation. The content
that can be used in the next stage is usually created in this stage. It includes modifying the surface of
object or material properties such as lighting, color, diffuse, and so on. The objects created in this stage
are in elementary or basic form which is helpful in the process of animation. Modeling of the object is
done with the aid of some software programs and applications.

Software programs used for modeling are:
1. Moray
2. Light wave modeler
3. Poser, Bryce
4. City Engine

Scene Layout Setup

It is the arrangement of virtual objects, cameras, lights and other units that are involved in the
production of still image or animation. This phase is known as key framing in animation. It aids in the
creation of complicated movements in scenes. The objects are set up in frames and the stages are added
into each of these frames.

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