Computer Graphics An Introduction Computer Graphics Whats this

Computer Graphics An Introduction

Computer Graphics What’s this course all about? We will cover… Graphics programming and algorithms Graphics data structures Colour and human vision Applied geometry, modelling and rendering 26/9/2008 Lecture 1 2

Computer Graphics is about animation (films) Major driving force now 26/9/2008 Lecture 1 3

Computer Graphics Games are very important in Computer Graphics 26/9/2008 Lecture 1 4

Computer Graphics Medical Imaging is another driving force Much financial support Promotes linking of graphics with video, scans, etc. 26/9/2008 Lecture 1 5

Computer Graphics Computer Aided Design too 26/9/2008 Lecture 1 6

Computer Graphics Scientific Visualisation To view below and above our visual range 26/9/2008 Lecture 1 7

Computer Graphics First Lecture • The graphics processes – What we will cover on this course • Some definitions – Fundamental units we use in these processes • Raster graphics implications • Course support resources 26/9/2008 Lecture 1 8

Computer Graphics Pipelines • Graphics processes generally execute sequentially • Typical ‘pipeline’ model • There are two ‘graphics’ pipelines – The Geometry or 3 D pipeline – The Imaging or 2 D pipeline 26/9/2008 Lecture 1 9

Computer Graphics Geometry Pipeline Animation/Interaction : time Modeling: shapes Shading: reflection and lighting Transformation: viewing Hidden Surface Elimination 26/9/2008 Lecture 1 Imaging Pipeline 10

Computer Graphics Imaging Pipeline Geometry Pipeline Rasterization and Sampling Texture Mapping Image Composition Intensity and Colour Quantization Framebuffer/Display 26/9/2008 Lecture 1 11

Computer Graphics An example thro’ the pipeline… The scene we are trying to represent: Images courtesy of Picture Inc. 26/9/2008 Lecture 1 12

Computer Graphics Wireframe model – Orthographic views 26/9/2008 Lecture 1 13

Computer Graphics Perspective View 26/9/2008 Lecture 1 14

Computer Graphics Depth Cue 26/9/2008 Lecture 1 15

Computer Graphics Hidden Line Removal – add colour 26/9/2008 Lecture 1 16

Computer Graphics Constant Shading - Ambient 26/9/2008 Lecture 1 17

Computer Graphics Faceted Shading - Flat 26/9/2008 Lecture 1 18

Computer Graphics Gouraud shading, no specular highlights 26/9/2008 Lecture 1 19

Computer Graphics Specular highlights added 26/9/2008 Lecture 1 20

Computer Graphics Phong shading 26/9/2008 Lecture 1 21

Computer Graphics Texture mapping 26/9/2008 Lecture 1 22

Computer Graphics Texture mapping 26/9/2008 Lecture 1 23

Computer Graphics Reflections, shadows & Bump mapping 26/9/2008 Lecture 1 24

Computer Graphics Definitions • Point – a location in space, 2 D or 3 D – sometimes denotes one pixel • Line – straight path connecting two points – infinitesimal width, consistent density – beginning and end on points 26/9/2008 Lecture 1 25

Computer Graphics Definitions • Vertex – point in 3 D • Edge – line in 3 D connecting two vertices • Polygon/Facet – arbitrary shape formed by connected vertices – fundamental unit of 3 D computer graphics 26/9/2008 Lecture 1 26

Computer Graphics Definitions • Raster – derived from TV systems for a row of pixels – commonly referred to as a scanline – does influence algorithms – reducing memory requirements, parallelism, etc. – is the derivation of rasterization, scan-line algorithms 26/9/2008 Lecture 1 27

Computer Graphics Course support resources • Graphics course website – lecture material, – lecture log with general summary and recommended reading, – Links to support material for lectures and projects, – Practical description and resources 26/9/2008 Lecture 1 28

Computer Graphics Summary • The course is about algorithms, not applications • Graphics execution is a pipelined approach • Most of the steps introduced with an example • Basic definitions presented • Some support resources indicated 26/9/2008 Lecture 1 29