1. 1 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 What is Computer Graphics? 靜宜大學 資訊工程系 蔡奇偉 副教授 2012 - 2014

2. 2 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Objectives In this lecture, we explore what computer graphics is about and survey some application areas We start with a historical introduction

3. 3 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Computer Graphics Computer graphics deals with all aspects of creating images with a computer ­Hardware ­Software ­Applications

4. 4 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Example Where did this image come from? What hardware/software did we need to produce it?

5. 5 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Preliminary Answer Application: The object is an artist’s rendition of the sun for an animation to be shown in a domed environment (planetarium) Software: Maya for modeling and rendering but Maya is built on top of OpenGL Hardware: PC with graphics card for modeling and rendering

6. Applications of CG Display Information ­Business Charts, Medical Images (CT, MRI, PET), Scientific Visualization Design ­CAD/CAM, VLSI Simulation Animation User Interface 6 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

7. Business Charts 7 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

8. Business Charts 8 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

9. Medical Images 9 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

10. Medical Images 10 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 A brain MRI representation

11. 11 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 In the high-resolution x-ray computed tomography (CT) images on the bottom, denser areas, such as bone, are brighter. In the fused view in the top three panels, the positron emission tomography (PET) image is overlaid, where hotter colors represent increased metabolic activity. Increased metabolism in the heart wall and brain are clearly visible. Also visible below the brain (middle PET image) is a focus of increased activity from a thyroid cancer. The combined anatomical and metabolic information was important for the planning of the successful surgery for the patient.

12. 12 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

13. Scientific Visualization 13 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 A scientific visualization of an extremely large simulation of a Rayleigh–Taylor instability caused by two mixing fluids.

14. Scientific Visualization 14 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Using visualization techniques, the overall 3D four-helix bundle structure of the molecule is represented as a ribbon model. The 3D image of this molecule helps researchers better understand it and its interaction with other molecules.

15. Scientific Visualization 15 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Solar system image of the main asteroid belt and the Trojan asteroids. Scientific visualization of Fluid Flow: Surface waves in water.

16. Design 16 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

17. Design 17 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

18. Design 18 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

19. Flight Simulator 19 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

20. Virtual Reality 20 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

21. Virtual Reality 21 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

22. Oculus Rift 22 Angel: Interactive Computer Graphics 4E © Addison-Wesley 2005

23. Samsung Gear VR 23 Angel: Interactive Computer Graphics 4E © Addison-Wesley 2005

24. Sony VR 24 Angel: Interactive Computer Graphics 4E © Addison-Wesley 2005

25. Animations 25 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

26. Graphical User Interface (GUI) 26 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 In computing, a graphical user interface (GUI, commonly pronounced gooey) is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand- held devices such as MP3 players, portable media players or gaming devices, household appliances and office equipment. A GUI represents the information and actions available to a user through graphical icons and visual indicators such as secondary notation, as opposed to text-based interfaces, typed command labels or text navigation. The actions are usually performed through direct manipulation of the graphical elements.

27. 27 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Basic Graphics System Input devices Output device Image formed in frame buffer

28. CRT 28 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Can be used either as a line-drawing device (calligraphic) or to display contents of frame buffer (raster mode)

29. Mask 29 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

30. Flat Panel Display 30 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012

31. 31 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Computer Graphics: 1950-1960 Computer graphics goes back to the earliest days of computing ­Strip charts ­Pen plotters ­Simple displays using A/D converters to go from computer to calligraphic CRT Cost of refresh for CRT too high ­Computers slow, expensive, unreliable

32. 32 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Computer Graphics: 1960-1970 Wireframe graphics ­Draw only lines Sketchpad Display Processors Storage tube wireframe representation of sun object

33. 33 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Sketchpad Ivan Sutherland’s PhD thesis at MIT ­Recognized the potential of man-machine interaction ­Loop Display something User moves light pen Computer generates new display ­Sutherland also created many of the now common algorithms for computer graphics

34. 34 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Display Processor Rather than have the host computer try to refresh display use a special purpose computer called a display processor (DPU) Graphics stored in display list (display file) on display processor Host compiles display list and sends to DPU

35. 35 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Direct View Storage Tube Created by Tektronix ­Did not require constant refresh ­Standard interface to computers Allowed for standard software Plot3D in Fortran ­Relatively inexpensive Opened door to use of computer graphics for CAD community

36. 36 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Computer Graphics: 1970-1980 Raster Graphics Beginning of graphics standards ­IFIPS ( International Federation of Information Processing Societies ) GKS: European effort –Becomes ISO 2D standard Core: North American effort – 3D but fails to become ISO standard Workstations and PCs

37. 37 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Raster Graphics Image produced as an array (the raster) of picture elements (pixels) in the frame buffer

38. 38 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Raster Graphics Allows us to go from lines and wire frame images to filled polygons

39. 39 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 PCs and Workstations Although we no longer make the distinction between workstations and PCs, historically they evolved from different roots ­Early workstations characterized by Networked connection: client-server model High-level of interactivity ­Early PCs included frame buffer as part of user memory Easy to change contents and create images

40. 40 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Computer Graphics: 1980-1990 Realism comes to computer graphics smooth shadingenvironment mapping bump mapping

41. 41 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Computer Graphics: 1980-1990 Special purpose hardware ­Silicon Graphics geometry engine VLSI implementation of graphics pipeline Industry-based standards ­PHIGS ­RenderMan Networked graphics: X Window System Human-Computer Interface (HCI)

42. 42 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Computer Graphics: 1990-2000 OpenGL API Completely computer-generated feature- length movies (Toy Story) are successful New hardware capabilities ­Texture mapping ­Blending ­Accumulation, stencil buffers

43. 43 Angel and Shreiner: Interactive Computer Graphics 6E © Addison-Wesley 2012 Computer Graphics: 2000- Photorealism Graphics cards for PCs dominate market ­Nvidia, ATI Game boxes and game players determine direction of market Computer graphics routine in movie industry: Maya, Lightwave Programmable pipelines