Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics CIS 736 Computer Graphics William H. Hsu Department of Computing and Information Sciences, KSU KSOL course pages: Course web site: Instructor home page: Readings: Handout 1: Texturing Sections 20.3 – 20.4, Eberly 2 e – see NeHe tutorials 6 (basics), 11 (flag), 15 & 17 (fonts) – More NeHe texturing tutorials: 35 (rendering), 42 (coloring) Advanced CG Topics 1 of 8: Filters for Texturing

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Online Recorded Lectures for CIS 736 Computer Graphics Project Topics for CIS 736 Advanced Topics in Computer Graphics (8)  1. Filters for Texturing – first month  2. More Mappings – second month  3. Advanced Lighting Models – second month  4. Advanced Ray-Tracing – first month  5. Advanced Ray-Tracing, concluded – second month  6. Global Illumination: Photon Maps (Radiosity) – third month  7. More on Scientific, Data, Info Visualization – third month  8. Terrain – first month Recommended Background Reading for CIS 736 Shared Lectures with CIS 636 (Computer Graphics)  Regular in-class lectures (35) and labs (7)  Guidelines for paper reviews – week of Mon 25 Feb 2008  Preparing term project presentations and demos for graphics – April

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Background Expected Both Courses  Proficiency in C/C++ or strong proficiency in Java and ability to learn  Strongly recommended: matrix theory or linear algebra (e.g., Math 551)  At least 120 hours for semester (up to 150 depending on term project)  Textbook: 3D Game Engine Design, Second Edition (2006), Eberly  Angel’s OpenGL: A Primer recommended CIS 636 Introduction to Computer Graphics  Fresh background in precalculus: Algebra 1-2, Analytic Geometry  Linear algebra basics: matrices, linear bases, vector spaces  Watch background lectures CIS 736 Computer Graphics  Recommended: first course in graphics (background lectures as needed)  OpenGL experience helps  Read up on shaders and shading languages  Watch advanced topics lectures; see list before choosing project topic

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Lecture Outline References: Gröller & Jeschke (2002), Isenberg (2005), Jacobs (2007) Texture Mapping Explained  Definitions  Design principles Texture Pipeline Using Simple Intermediate Surfaces (Cylinder, Sphere, Plane, Box) Procedural Textures  Simple regular patterns (e.g., checkerboard)  Terrain  Clouds Perlin Noise Models  Interpolation  Turbulence Later: Relation to Fractals, Fractional Brownian Motion (fBm) Anisotropic Filtering

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Source Material: Gröller & Jeschke ICGA, Vienna Institute of Technology Adapted from slides © 2002 Gröller, E. & Jeschke, S. Vienna Institute of Technology

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Other Source Material: CMSC 427 Computer Graphics University of Maryland – College Park (UMD) Fall 2007 Course: Instructor: Tobias Isenberg Scientific Visualization and Computer Graphics Group Department of Mathematics and Computing Science University of Groningen Formerly Graphics Jungle Lab Department of Computer Science University of Calgary CPSC / Computer Graphics Fall 2005 Course: Instructor:

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Why Texturing? Adapted from slides © 2002 Gröller, E. & Jeschke, S. Vienna Institute of Technology

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Introduction [1]: Motivation Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen)

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Introduction [2]: Properties and their Mappings

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Concerning Textures Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Without Textures Adapted from slides © 2007 Jacobs, D. W., University of Maryland From Computer Graphics: Principles and Practice © 1991 Foley, van Dam, Feiner, Hughes

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics With Textures Adapted from slides © 2007 Jacobs, D. W., University of Maryland From Computer Graphics: Principles and Practice © 1991 Foley, van Dam, Feiner, Hughes

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Texture Image Adapted from slides © 2007 Jacobs, D. W., University of Maryland u v

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Texture Mapping How-To [1]: Goals and Texture Elements (Texels)

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Texture Mapping How-To [2]: Adapting Polygons-to-Pixels Pipeline

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Texture Mapping How-To [3]: Mapping Definition u = s(x, y, z) v = t(x, y, z)

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Texture Mapping How-To [4]: General Procedure

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Texture Mapping How-To [5]: Projective Textures, Projector Functions

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Texture Mapping How-To [6]: (Manual) Surface Parameterization

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Texture Mapping How-To [6]: Inherent (u, v) Coordinates

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Two-Step Approach [1]: Duality (Again)

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Two-Step Approach [2]: Example – Cylindrical Mapping

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Two-Step Approach [3]: Example – Spherical Mapping

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Two-Step Approach [4]: Example – Planar Mapping

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Two-Step Approach [5]: Example – Cuboid/Box Mapping

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) O Mapping [1]: Object-to-Surface

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) O Mapping [2]: Illustrations 1. Reflected Ray2. Object Normal 3. Object Center 4. Normal of Intermediate Surface

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Correspondence Functions [1]: Texture Coordinates u = s(x, y, z) v = t(x, y, z)

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Correspondence Functions [2]: Tiling, Mirroring, Clamping, Borders

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Correspondence Functions [3]: Clamping and Borders Illustrated

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Application of Texture Values: Combining Texturing and Lighting

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) The End…? Done! … well, almost

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2005 Isenberg, T., University of Calgary (now at U. Groningen) Acknowledgements

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Surface Detail: Imitating Complexity by Texturing Smooth Objects Adapted from slides © 2002 Gröller, E. & Jeschke, S. Vienna Institute of Technology

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Texture Properties Adapted from slides © 2002 Gröller, E. & Jeschke, S. Vienna Institute of Technology Procedural: either

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Texture [1] Adapted from slides © 2007 Jacobs, D. W., University of Maryland … how to get this?

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Texture [2] Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Texture [3] Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Texture [4] Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Adapted from slides © 2007 Jacobs, D. W., University of Maryland Procedural Models: Example [1]

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Models: Example [2] Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Models: Example [3] Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Models: Example [4] Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Models: Example [5] Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics What is Texture? Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Perlin Noise [1]: How to Simulate Variation Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Perlin Noise [2]: Properties Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Textures: Strategy Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics 1-D Perlin Noise Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics 2-D Perlin Noise Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Smooth Noise Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Linear Interpolation Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Cubic Interpolation Adapted from slides © 2007 Jacobs, D. W., University of Maryland … more on this later: Splines Bezier curves Bicubic surfaces

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Gradient (Perlin) Noise Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Perlin Noise: Example Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Perlin Noise Mixtures [1]: Idea Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Perlin Noise Mixtures [2]: Example Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Perlin Noise Mixtures [3]: Texture Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Turbulence [1]: Using Perlin Noise Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Turbulence [2]: Example Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Procedural Turbulence [3]: Texture Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics More Procedural Textures Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Example with Illumination Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Nonlinear Changes in Intensity Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics 3-D Textures Adapted from slides © 2007 Jacobs, D. W., University of Maryland © 2007 Feiner, S. & Nayar, S. K. Computer Vision Lab Department of Computer Science Columbia University

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics OpenGL Texturing [1]: Steps Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics OpenGL Texturing [2]: Specify 2-D Texture Object Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics OpenGL Texturing [3]: Specify How Texture Is Applied Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics OpenGL Texturing [4]: Enable Texture and Draw Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics OpenGL Texturing [5]: Create Texture Object Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics OpenGL Texturing [6]: Putting It All Together Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Texture Synthesis: Goal Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Texture Synthesis: Goal Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Texture Synthesis: Probabilistic Modeling Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Texturing: Like Copying, but Not Just Repetition Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Texturing with Blocks [1]: Technique Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Texturing with Blocks [2]: Examples Adapted from slides © 2007 Jacobs, D. W., University of Maryland

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Summary Textures  Definitions  Design principles Texture Pipeline  Part of polygons-to-pixels  Uses same spaces (coordinate systems) and more Using Simple Intermediate Surfaces (Cylinder, Sphere, Plane, Box) Procedural Textures  Simple regular patterns (e.g., checkerboard)  Other textures: terrain, clouds, etc. Perlin Noise Models  Interpolation approach  Turbulence for material properties Anisotropic Filtering References: Gröller & Jeschke (2002), Isenberg (2005), Jacobs (2007)

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Terminology Texture Coordinate Systems (Spaces)  Model / Object: 3-D (x, y, z)  World / Scene: 3-D (x, y, z)  Camera / Eye: 3-D (u, v, n)  Window / Screen: 2-D (u, v)  Texture: 1-D, 2-D, or 3-D; (s, t) for 2-D Texture Pipeline Perlin Noise  Interpolation  Turbulence for material properties Anisotropic Filtering References: Gröller & Jeschke (2002), Isenberg (2005), Jacobs (2007)

Computing & Information Sciences Kansas State University Advanced CG 1 of 8: TexturingCIS 636/736: (Introduction to) Computer Graphics Next: Animation (Class), Ray Tracing (736) Vicki Shreiner: Animation and Depth Buffering  Double buffering  Lights: positioning  Illumination: light models, attenuation  Material properties  Animation basics in OpenGL Vicki Schreiner: Imaging and Raster Primitives Ed Angel: Texture Mapping Dave Shreiner: Advanced Topics  Display lists and vertex arrays  Accumulation buffer  Fog  Stencil buffering  Fragment programs (to be concluded in Tutorial 3)