1 COMPUTER GRAPHICS.ppt

What Is Computer Graphics?
The creation , manipulation , analysis , and interaction with pictorial
representations of objects and data using computers.
More precisely: image synthesis

WHY COMPUTER GRAPHICS?
•About 50% of the brain neurons are associated with vision
•Dominant form of computer output
•Enrich the discovery process and facilitate new inventions

GOALS OF COMPUTER GRAPHICS
 Generate synthetic images
 Do it in a practical way & scientifically sound.
 And make it look easy…

USES OF GRAPHICS
• Special effects
• Feature animation
• Computer Games
• Virtual environments
• Visualization
(science, business, cartography, ...)
• Design
• Interaction

SCIENTIFIC VISUALIZATION / SIMULATION
ELECTROMAGNETIC POTENTIAL FIELD COMPUTATIONAL FLUID DYNAMICS
(CFD)

VIRTUAL REALITY
Virtual tour of historical remains

IMAGE PROCESSING, ANALYSIS, AND
SYNTHESIS

COMPUTER ART-DIGITAL CALLIGRAPHY

MOVIES
If you can image it, it can be done with computer graphics!
More than one billion dollars on special effects.
No end in sight for this trend!

2. HARDWARE AND
SYSTEM
ARCHITECTURE

ANIMATION
Model how things move
• Temporal change of
– Objects (position, orientation, size, shape, color, etc.)
– Camera (position, direction, angle, focus, etc.)
– Illumination (position, direction, color, brightness)
• Represent motion
– Sequence of stills
– Parameter curves

MODELING
How to represent real environments
– Geometry: curves, surfaces, volumes
– Photometry: light, color, reflectance
• How to build these representations
– Interactive: sculpt it
– Algorithmic: let it grow (fractals, extraction)
– Scanning: via 3D sensing
• Generate primitives
– Lines, triangles, quads, patches
– Cylinder, spheres
– Higher-order primitives

COMPUTER GRAPHICS
BASIC
PRINCIPLES AND
CONCEPTS

1. PIXEL
Pixels are placed on a regular 2-dimensional grid,
and are often represented using dots or squares.
Each pixel is a sample of an original image, where
more samples typically provide a more accurate
representation of the original.
The intensity of each pixel is variable; in color
systems, each pixel has typically three
components such as red, green, and blue.

2. GRAPHICS
 Graphics are visual presentations on a surface, such as a
computer screen. Examples are photographs, drawing, graphics
designs, maps, engineering drawings, or other images.
 Graphics often combine text and illustration. Graphic design
consist of the deliberate selection, creation.

3. RENDERING
 Rendering is the generation of a 2D image from a 3D model by means of
computer programs.
 A scene file contains objects in a strictly defined language or data structure;
it would contain geometry, viewpoint, texture, lighting, and shading information
as a description of the virtual scene.
 The rendering program is usually built into the computer graphics software.
The term "rendering" may be by analogy with an "artist's rendering" of a scene.

4. 3D PROJECTION
 3D PROJECTIONS is a method
of mapping 3D points to a 2D
plane.
 Current methods for
displaying graphical data are
based on planar two
dimensional media, the use of
this type of projection is
widespread, especially in
C.G, engineering and

5. RAY TRACING
 Ray tracing is a method for creating
an image by tracing the path of light
via pixels in an image plane.
 The technique is able of creating a high
degree of photorealism; commonly higher
than that of usual scan line
rendering methods with a
greater computational cost.

6. SHADING
 Shading refers to depicting depth in three
dimensional models by changing levels
of darkness.
 There are different techniques of shading
with cross hatching where perpendicular lines of
changing closeness are drawn in a grid pattern to
shade a boundary.
 The closer the lines are jointly, the darker
the area shows. Likewise, the beyond apart the
lines are, the lighter the area shows.

7. TEXTURE MAPPING
Texture mapping is the process of mapping an image onto a triangle
in order to increase the detail of the rendering.
The image that gets mapped onto the triangle is called a texture
map or texture and is usually a regular color image.

1 COMPUTER GRAPHICS.ppt

More Related Content

Similar to 1 COMPUTER GRAPHICS.ppt (20)

Recently uploaded (20)

1 COMPUTER GRAPHICS.ppt