Advanced Computer Graphics (Spring 2005) COMS 4162, Lecture 1: Overview Ravi Ramamoorthi

Goals  Systems: Write fairly complex programs for image processing, mesh algorithms, image synthesis  Theory: Understand mathematical aspects and algorithms underlying modern 3D graphics [Fourier analysis+sampling theory, mesh geometric data structures, Monte Carlo rendering, integration]  This course is a continuation of COMS 4160, intro graphics. It fills in some of the gaps there, and provides a more advanced thorough overview

Course Outline  3D Graphics Pipeline Rendering (Creating, shading images from geometry, lighting, materials) Modeling (Creating 3D Geometry)

Course Outline  3D Graphics Pipeline Rendering (Creating, shading images from geometry, lighting, materials) Modeling (Creating 3D Geometry) Unit 1: Foundations of Signal and Image Processing Understanding the way 2D images are formed and displayed, the important concepts and algorithms, and to build an image processing utility like Photoshop Weeks 1 – 3. Assignment 1 due Feb 15

Course Outline  3D Graphics Pipeline Rendering (Creating, shading images from geometry, lighting, materials) Modeling (Creating 3D Geometry) Unit 1: Foundations of Signal and Image Processing Understanding the way 2D images are formed and displayed, the important concepts and algorithms, and to build an image processing utility like Photoshop Weeks 1 – 3. Assignment 1 due Feb 15 Unit 2: Meshes, Modeling Weeks 4 – 6. Ass 2 due Mar 10

Course Outline  3D Graphics Pipeline Rendering (Creating, shading images from geometry, lighting, materials) Modeling (Creating 3D Geometry) Unit 1: Foundations of Signal and Image Processing Understanding the way 2D images are formed and displayed, the important concepts and algorithms, and to build an image processing utility like Photoshop Weeks 1 – 3. Assignment 1 due Feb 15 Unit 2: Meshes, Modeling Weeks 4 – 6. Ass 2 due Mar 10 Unit 3: Ray Tracing Weeks 7 – 9. Ass 3 due Apr 12 Unit 4: Advanced Topics Weeks 10+. Ass 4 (final project) due May 2

Logistics  Website has most of information (look at it)  Office hours: after class (or just send me )  TA: Bo Sun, CEPSR 615  Course bulletin board to be set up, class TA  TA office hours etc after next week of lectures  Textbook: Computer Graphics Principles and Practice by Foley, van Dam, Feiner, Hughes

Workload  Challenging course: Lots of fun, rewarding but may involve significant work (like 4160, perhaps more understanding, a little less actual code)  4 programming projects. All are significant effort, real systems. Also require well documented reports (websites). Challenging but fun  But most of you built games. I don’t think workload substantial relative to that  You have 3-4 weeks. Project scope assumes you actually work on them for 3-4 weeks. START EARLY and work steadily.  Groups of 2 quasi-required (you can work alone, but at your own risk)  Assignments 1-3 also have written questions that test understanding of mathematical and geometrical concepts taught  Also done in groups of 2 as for programming. Start early here too  No midterms or finals  Prerequisites: COMS 4160 or equivalent intro to graphics  Note: some overlap possible for those who took intro graphics elsewhere. Have fun and relax on those parts, or go overboard…  Generously graded: You did well in 4160, here to have fun, learn graphics. Don’t really worry about scores and grades. Just do work, have fun

Related courses  COMS 4167, on animation Prof. Grinspun this semester  Many 6000-level courses (e.g. COMS 6160 High Quality Real-Time Rendering taught by me last fall) if you are still here next year  Part of Vision and Graphics track in BS and MS programs. Columbia Vision and Graphics Center  Other related courses: Computer Vision, Robotics, User Interfaces Computational Geometry, …

To Do  Look at website  Various policies etc. for course. Send me if confused.  Skim assignments if you want. All are tentatively ready (except for assignment 1, which is released)  Assignment 0, Due Jan 20 tomorrow (see website). Send e- mail to telling us about yourself and sending us a digital photo if possible (to put names to faces).  Assignment 1, Due Feb 15. Start working on it next week, but for now, make sure you can download and compile  Find partners for assignment 1 and possibly later. Does anyone need help? Any other questions?

History  Brief summary of course in context of history of field

2D Graphics Many of the standard operations you’re used to :  Text  Graphical User Interfaces (Windows, MacOS,..)  Image processing and paint programs (Photoshop, …)  Drawing and presentation (Powerpoint, …)

 SuperPaint system: Richard Shoup, Alvy Ray Smith (PARC, )  Nowadays, image processing programs like Photoshop can draw, paint, edit, etc. Paint Systems

 Digitally alter images, crop, scale, composite  Add or remove objects  Sports broadcasts for TV (combine 2D and 3D processing) Image Processing

Relevance to Course  In 4160, didn’t cover 2D at all  But relevant broadly (not just for 2D), since ultimately 3D scene displayed as 2D image  In 4162, we cover image processing and many photoshop functions [assignment to write a mini-version]

Modeling  Spline curves, surfaces: 70 s – 80 s  Utah teapot: Famous 3D model  More recently: Triangle meshes often acquired from real objects

Relevance to Course  Covered Bezier, B-spline curves for modeling in 4160 Will talk briefly about NURBS, surfaces in 4162  Main idea is to talk about mesh processing algs.  Will learn to represent, work with meshes  Do mesh simplification, progressive meshes

Progressive Mesh Movie

Rendering: 1960s (visibility)  Roberts (1963), Appel (1967) - hidden-line algorithms  Warnock (1969), Watkins (1970) - hidden-surface  Sutherland (1974) - visibility = sorting Images from FvDFH, Pixar’s Shutterbug Slide ideas for history of Rendering courtesy Marc Levoy

1970s - raster graphics  Gouraud (1971) - diffuse lighting, Phong (1974) - specular lighting  Blinn (1974) - curved surfaces, texture  Catmull (1974) - Z-buffer hidden-surface algorithm Rendering: 1970s (lighting)

Rendering (1980s, 90s: Global Illumination) early 1980s - global illumination  Whitted (1980) - ray tracing  Goral, Torrance et al. (1984) radiosity  Kajiya (1986) - the rendering equation

Relevance to Course  We didn’t talk about visibility algorithms in 4160  Nowadays, simple Z-buffer used OpenGL  Discussed illumination and shading models  And theory (but not practice) of global illumination  In 4162, we will cover practical global illum.  First, build a simple ray tracer  Extensions/final project related to rendering

Image Synthesis Examples

Summary  COMS 4160 covered basics of computer graphics  Theory of transformations, curves, illumination  Building complex interactive graphics programs  COMS 4162 covers more advanced topics and fills in the gaps in Essential for full graphics intro  2D Image and Signal Processing (+Fourier analysis)  Mesh algorithms (+Mesh geometric data structures)  Ray Tracing (+Monte Carlo sampling for rendering)  Advanced Rendering and other topics