Computer Graphics Introduction
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Transcript of Computer Graphics Introduction
![Page 1: Computer Graphics Introduction](https://reader030.fdocuments.us/reader030/viewer/2022032612/568131a5550346895d981470/html5/thumbnails/1.jpg)
Computer GraphicsIntroduction
![Page 2: Computer Graphics Introduction](https://reader030.fdocuments.us/reader030/viewer/2022032612/568131a5550346895d981470/html5/thumbnails/2.jpg)
Graphics: All aspects of the production of pictures (images) using a computer
Application areas:
Display of Information
Design
Simulation
User Interfaces
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Basic Graphics System:
Processor
Memory
Frame buffer
Output device
Input device
Basic Graphics System:
Processor
Memory
Frame buffer
Output device
Input device
Basic Graphics System:
Processor
Memory
Frame buffer
Output device
Input device
Basic Graphics System:
Processor
Memory
Frame buffer
Output device
Input device
Basic Graphics System:
Processor
Memory
Frame buffer
Output device
Input device
Basic Graphics System:
Processor
Memory
Frame buffer
Output device
Input device
![Page 4: Computer Graphics Introduction](https://reader030.fdocuments.us/reader030/viewer/2022032612/568131a5550346895d981470/html5/thumbnails/4.jpg)
Pixels & Frame buffer
Raster: array of pixels
Pixel: picture element
Frame Buffer: memory area used to store pixel/raster data
DRAM: Dynamic random access memory
Depth: number of bits of information stored
for each pixel
Resolution: number of pixels in frame
buffer (on screen)
VRAM: Video random access memory
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Processor:
- may be main CPU or special purpose processor on video card
- performs Rasterization (Scan Conversion) conversion of geometric primitives (line, circle, etc) to pixel values in frame buffer
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Output devices
CRT: Cathode Ray Tube
refresh
flicker
triads
shadow mask
LCD: Liquid crystal display
CRT: Cathode Ray Tube
refresh
flicker
triads
shadow mask
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Refresh
RASTER SCAN
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Output devices
CRT: Cathode Ray Tube
refresh
flicker
triads
shadow mask
![Page 9: Computer Graphics Introduction](https://reader030.fdocuments.us/reader030/viewer/2022032612/568131a5550346895d981470/html5/thumbnails/9.jpg)
TRIAD
SHADOWMASK
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Vector Displaysgraphics primitives are made of sequences of strokes or vectors
Raster Displaysdisplay graphics primitives in a refresh buffer in terms of the primitive’s component pixels
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Vector Displaysgraphics primitives are made of sequences of strokes or vectors
IDEAL LINE DRAWING RANDOM SCAN
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Raster Displaysdisplay graphics primitives in a refresh buffer in terms of the primitive’s component pixels
IDEAL LINE DRAWING RASTER SCAN
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Raster Displaysdisplay graphics primitives in a refresh buffer in terms of the primitive’s component pixels
IDEAL LINE DRAWING FILLED RASTER SCAN
![Page 14: Computer Graphics Introduction](https://reader030.fdocuments.us/reader030/viewer/2022032612/568131a5550346895d981470/html5/thumbnails/14.jpg)
IMAGES:
Point: a location on an object (or in space) relative to a Reference Coordinate System
Cartesian Coordinates: 3D space, perpendicular axes, equal distance measures on each axis
Object: specified by an organized grouping of Metric and topological information
Vertices: corner points. They carry metric information -- (X,Y,Z) coordinates.
Vertex listing: list of vertex identifiers forming polygon boundary (usually a list of indices into the vertex array)
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What must be specified (known)
1 - What are the objects in the scene
2 - Where are the objects in the scene
3 - Where is the viewer
4 - Where is the viewer looking
5 - What type of projection is assumed
6 - Where are the lights
7 - ....
4 - Where is the viewer looking
1 - What are the objects in the scene
2 - Where are the objects in the scene
3 - Where is the viewer
6 - Where are the lights
5 - What type of projection is assumed
Image creation:NOTE: An image is generally a 2D projection or rendering of a 3D scene
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Light: visible part of the electromagnetic spectrum
Wavelength: identifies light color (350-780 nanometers)
Light sources characterized by location, nature (point or area), color, brightness
(Simplifying assumption for now -- assume monochromatic (single color) lights)
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Ray tracing is a method for following the path of a photon from its origin at a light source, bouncing off the various surfaces it strikes, before it strikes the image plane.
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The Pinhole Camera
Simple model for a camera.
The pinhole allows only a small number of light rays to pass through from the scene to the film.
Film
Pinhole
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Computer graphics model of pinhole camera
Eye
The pinhole is replaced by the eye and the film plane moves out in front of the pinhole (eye).