1_ Intro___________DONE.pdf

Computer Graphics General Introduction Computer Graphics Course Dr. Ammar Alnahhas 1 /112  Prerequisites  Fundamental CS background  Knowledge of geometric aspects of graphics  Programming language skills  Mathematical sophistication....

Computer Graphics General Introduction Computer Graphics Course Dr. Ammar Alnahhas 1 /112  Prerequisites  Fundamental CS background  Knowledge of geometric aspects of graphics  Programming language skills  Mathematical sophistication. 2 /112  Computer Graphic: Definitions One could classify the topics of graphic treatment by computer in two categories: Sampled-based graphics Geometry-based graphics 3 /112  Computer Graphic: Definitions Sampled-based graphics Sampled-based graphics is commonly understood to mean the creation, storage and treatment of images. 4 /112  Sampled-based graphics  Sampled-based graphics: images are used to describe visual information,  Images are made up of a grid of discrete pixels “picture elements” for 2D light intensity,  Pixels can be created by digitizing images, using several devices,  Pixels are point locations with associated sample values, usually of light intensities/colors,  Pixel information from one image can be copied and pasted into another,  Once an image is defined as a pixel-array, it can be manipulated: 5 /112 Sampled-based graphics Real Image Input Numerical Image 6 /112  Sampled-based graphics  image editing: describes changes made by a user to an image, such as cutting and pasting sections, using brush-type tools, and processing selected areas.  image processing: describes algorithmic operations that are performed on an image (or preselected portion of an image) without user intervention.  These include such operations as blurring, sharpening, edge- detection, color balancing, rotating and warping.  Example programs: Adobe Photoshop, The GIMP 7 /112  Sampled-based graphics Sampled-based graphics Subareas:  Image Processing: a series of Real Image image transformations; Input Numerical Image ALGORITMES image → image Analysis Processing Model 8 /112  Sampled-based graphics Sampled-based graphics Subareas:  Computer vision: extraction of 3D Real Image information from 2D image Input Numerical Image ALGORITMES Analysis Processing image → Model Model 9 /112  Sampled-based graphics Real Image  Image Processing Applications:  Aerial Surveillance photographs, Input  Television images,  X-ray images, Numerical  Optical Character Recognition: Image OCR,  Robotics. ALGORITMES Analysis Processing Model 10 /112  Computer Graphic: Definitions Geometry-based graphics 0010101010 Computer graphics is commonly understood to mean the creation, storage and manipulation of models. 11 /112  Geometry-based graphics  Geometry-based graphics: store mathematical descriptions, or “geometrical model ” of geometric elements (lines, polygons, polyhedrons...) and their associated attributes (e.g., color, material properties),  These elements are primitive geometric shapes, primitives for short.  Geometrical model then sampled for visualization (this process is called rendering),  example programs: Adobe Illustrator, Claris’s MacDraw Autodesk’s AutoCAD and Studio 3D, Alias|Wavefront Studio and Maya, SoftImage 3D. 12 /112  Geometry-based graphics G U I (Interaction) User controls contents, structure, and MODELING RENDERING DISPLAYING appearance of objects and ( to describe) (to capture) (to show) their displayed to the computer the description the image images via what is create 2D image generate rapid visual a table from 2D / 3D image on feedback a car models screen Geometric Engine Rendering Engine Raster & Display Engine concerned with: concerned with : concerned with:  geometry transformations  hardware  object geometry  viewing & projection  how to display  color models  texture mapping  material property  drawing & clipping primitives  local illumination & shading  lighting property  global rendering 13 /112  Computer Graphic: Definitions Mix of theory and applications Physics Computer Science Geometric CG Hardware Mathematics 14 /112 Geometry-based graphics Sampled-based graphics Image synthesis Real Image Output Input Numerical Numerical Image Image Synthesis ALGORITMES ALGORITMES Analysis Processing Model 15 /112  History of Standards Computer Graphics Software  OPENGL  It was originally developed by SGI as a hardware independent,  Provides a powerful primitive set of rendering commands (functions) to produce high-quality color images of 2D or 3D objects. All higher-level drawing must be done in terms of these commands.  The basic graphics functions with about 120 functions are stored in the main library GL. 16 /112  History of Standards Computer Graphics Software  OPENGL  Additional libraries are needed to allow programmers to work easily with the windowing system and the I/O subsystem. These libraries include:  GLU (OpenGL Utility Library)  GLUT (OpenGL Utility ToolKit)  GLX (OpenGL Extension to the X window System) 17 /112  Overview of Computer Graphics applications  Business, science, and technology,  Training: Simulated environments, Virtual Reality,  Multimedia systems, WWW: graphical design,  Communications, interface, interaction,  Physical process, chemical reaction, nuclear process,  Science: Mathematics, physics (differential equations,  Engineering (computational fluid dynamics). 18 /112  General References  Computer Graphics: Principles and Practice (2nd Ed.), J. D. Foley, A. van Dam, S. K. Feiner, J. F. Hughes. Addison-Wesley, 1997.  Computer Graphics (2nd Ed.), D. Hearn et M. Baker. Prentice-Hall, 1994.  Introduction to Computer Graphics, J. D. Foley, A. van Dam, S. K. Feiner, J. F. Hughes. Addison-Wesley, 1990.  Principles of Interactive Computer Graphics (2nd Ed.), William Newman, Robert Sproull. McGraw Hill, 1979. 19 /112  General References  A. Watt 3D Computer Graphics. (2nd Ed.), Addison- Wesley, 1993.  Rogers, David. Procedural Elements for Computer Graphics. New York, NY: McGraw-Hill Book Company, 1985.  A. Watt et M. Watt Advanced Rendering and Animation Techniques: Theory and Practice. Addison-Wesley, 1991.  Infographie I et II: Philippe Schweizer Collection Informatique Presses Polytechniques Romandes 20 /112  General References  OpenGL, reference manual: The official reference document OpenGL architecture review board Addison Wesley  M. Woo, J. Neider, T. Davis, D. Shreiner OpenGL® Programming Guide: The Official Guide to Learning OpenGL, Version 1.2. (3nd Ed.) , Addison-Wesley, 1997 21 /112