Computer Graphics. Instructor: Oren Kapah. Office Hours: T.B.A.

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Computer Graphics Instructor: Oren Kapah (orenkapahbiu@gmail.

1 Computer Graphics Instructor: Oren Kapah Office Hours: T.B.A. The CG-IDC slides for this course were created by Toky & Hagit Hel-Or 1

2 CG-IDC 2

3 Exercise and Homework The exercise will cover practical aspects of the material taught in class. OpenGL will be covered in the exercise. Homework will be written in OpenGL and Java Homework may be submitted in pairs (No triplets). In general - two weeks due date. No exercise this week. CG-IDC 3

4 Grading Policy: 50% homework assignments+50% exam. Homework assignments are weighted. Exam will include class and exercise material. Homework appeals can be submitted no later than one week after they re returned! IMPORTANT! You must pass the exam in order to pass the course. CG-IDC 4

5 Course Web site: Lessons (PDF format). Homework. Handouts and program examples. Grades. News. Mailing Group CG-IDC 5

6 Books Computer Graphics Hearn and Baker Second Edition, Prentice Hall, Computer Graphics Principles and Practice, Foley, Van Dam, Feiner, and Hughes Second Edition, Addison Wesley, Mathematical Elements for Computer Graphics Rogers and Adams Second edition, McGraw-Hill, OpenGL SuperBible S. Richard, JR Wright, M. Sweet Waite Group Press CG-IDC 6

7 Goals: Implementing Practical Math. Getting acquainted with graphical models, basic techniques, and algorithms. Getting acquainted with a Graphical Language (OpenGL). CG-IDC 7

8 The Visual Sciences Image Processing Image Computer Vision Rendering 3D Object Geometric Modeling Model CG-IDC 8

9 Context Image Processing: images => images Computer Vision: images => models Computer Graphics: Geometric Modeling: object => models 3D-rendering: 2D/3D models =>images Animation: 4D models => images. CG-IDC 9

10 Applications CAD - Computer Aided Design (mechanical, architectural) Simulators (flight, driving) Architectural visualization Advertising Virtual Reality Art Games Special effects Education Scientific visualization CG-IDC 10

11 Tin Toy Pixar 1988 CG-IDC 11

12 Rendered image CG-IDC 12

13 Rendered image Lighting Geometry Material properties &Texture Viewing CG-IDC 13

14 Reality Non realistic rendering CG-IDC 14

15 Photo-realistic rendering CG-IDC 15

16 Non-realistic rendering Pensive CG-IDC 16

17 Viewing Factors Camera: Projections Solid modeling Object s Geometrical properties Light Source: Color theory Objects: Y Y Z X Illumination & Color Models. object s surfaces physical properties Spatial set-up: 3D transformations, Coordinate Systems. CG-IDC 17

18 Scope and Course Flow: 2D Drawing. Vector analysis. 2D transformations. 2D viewing. 3D transformations. 3D Modeling. 3D viewing Color Models. Shading Models. CG-IDC 18

19 Drawing in 2D Goal: Getting acquainted with images. Displays types (raster vs. vector). Basic image definitions: Pixel, Resolution, dynamic range Scan conversion: Techniques for Line drawing Techniques for drawing circles. Fill polygons. CG-IDC 19

20 Vector Analysis Goal: Refreshing Linear Algebra basics. Mathematical entities: Scalar, Points, Vectors. Fundamental operations: point+vector, vector+vector, vector*scalar, dot product, cross product, etc. Vector representation - the basis. Point representation - the frame. CG-IDC 20

21 Transformations in 2D Goal: Introduction to 3D. Basic 2D transformations: Translation, Scaling, Rotation, Shear. Composition of transformations and transformation groups: Affine Similarity Rigid CG-IDC 21

22 CG-IDC 22 Transformations in Matrix notation: Composition of transformations in matrix notation. The homogeneous coordinates in 2D: Change of coordinates: y x d c b a y x ' ' x y x y ),, ( ),, ( ), ( t ty tx W Y X y x

23 Viewing in 2D Goal: Preperation to 3D and some rendering concepts. Viewing transformation pipe-line: y world x world Clipping Line and Polygon Clipping techniques: CG-IDC 23

24 Transformations in 3D Goal: Geometrical transformations to be used in viewing pipe-line. Similar to 2D but in 3D. CG-IDC 24

25 Viewing in 3D Goal: Geometrical transformations in viewing pipe-line. From Model coordinates to Viewer coordinates. world z w Body System x w y w y v x v Front- Wheel System P 0 Viewer System z v CG-IDC 25

26 Projections: Orthographic. Oblique. Perspective. The Viewing Volume: y v near x v z v far CG-IDC 26

27 Solid Modeling Goal: Learn how to define solid objects. 1D Curves in 3D Primitive based: line segments. Free form: Implicit, Explicit, Parametric (polynomials, splines) 2D Surfaces in 3D Primitive Based: Polygon mesh. Free Form: As above CG-IDC 27

28 3D volumes in 3D Volume Rep. Sweep volumes Spatial Occupancy(voxels, Octree, BSP) Constructive Solid Geometry Boundary Rep. Polyhedra Free form: as above CG-IDC 28

29 Approximated/Interpolated Parametric Surfaces Bilinear interpolation. Splines: Cardinal spline. Hermite spline. Bezier Spline. B spline. CG-IDC 29

Color Theory Goal: Understanding what a color is. The Trichromatic Color Theory. Linear color space and color representations: RGB, CMY,HSB. Perceptual color spaces: LAB,YIQ.

30 Color Theory Goal: Understanding what a color is. The Trichromatic Color Theory. Linear color space and color representations: RGB, CMY,HSB. Perceptual color spaces: LAB,YIQ. The CIE Chromaticity Diagram G green B y cyan yellowgreen yellow 590 orange 600 white 610 pink red 650 R Brightness 485 blue 480 purple magenta x Hue CG-IDC 30

31 Illumination Models & Shading Goal: Understanding the physical properties of an object. Light source parameters (shape, position, color, intensity). Surface parameters: Ambient, diffuse, specular. Polygon Rendering methods. Transparency. Shadow. CG-IDC 31

32 Ambient, Diffuse, and Specular components CG-IDC 32

33 Composition of Light Sources

35 Image based lighting CG-IDC 35

36 Example: A Sequence of creating an images from a given model. (from Foley Van Dam) CG-IDC 36

37 Polygonal model generated from spline patches. Orthographic projection Polygonal model generated from spline patches. Perspective projection CG-IDC 37

38 Depth cueing. CG-IDC 38

39 Depth Clipping Colored vectors. CG-IDC 39

40 Hidden line removal Visible surface determination with ambient illumination CG-IDC 40

41 Individually shaded polygon with diffuse reflection Gouraud shaded polygon with diffuse reflection CG-IDC 41

42 Gouraud shaded polygon with specular reflection Phong shaded polygon with specular reflection CG-IDC 42

43 Curved surfaces with specular reflection multiple lights CG-IDC 43

44 Texture mapping shadows CG-IDC 44

45 Final image CG-IDC 45

46 Pixar 1986 best of Siggraph 1986 CG-IDC 46

47 Real time off line rendering CG-IDC 47

48 CG-IDC 48

Course Title: Computer Graphics Course no: CSC209

Course Title: Computer Graphics Course no: CSC209 Nature of the Course: Theory + Lab Semester: III Full Marks: 60+20+20 Pass Marks: 24 +8+8 Credit Hrs: 3 Course Description: The course coversconcepts of