Computer Graphics Overview

CMSC 435/634

1 Graphics Areas

• “Core” graphics areas – Modeling – Rendering – Animation – Imaging • Other areas which draw on computer graphics – User Interaction – Virtual Reality – Visualization – Image Processing – 3D Scanning 2 Graphics Areas – Modeling

• Deals with the mathematical specification of shape and appearance – Definition of surface – Interpolation rules – Reflection models

3 Graphics Areas – Modeling

4 Graphics Area – Modeling

5 Shutterbug Image Series - Pixar Graphics Areas – Rendering

• Term inherited from art – create shaded images from computer models – Many techniques – Many styles of rendering

6 Graphics Areas – Rendering

7 J*sola Graphics Areas – Rendering

8 Finlay McWalter Graphics Areas – Rendering

9 Policarpo, F., Oliveira, M. M., and Comba, J. L. 2005. Real-time relief mapping on arbitrary polygonal surfaces Graphics Areas – Rendering

10 Anton L. Fuhrmann Graphics Areas – Rendering

11 Realistic Image Synthesis Engine (R.I.S.E.) Gallery Graphics Areas – Rendering

12 Realistic Image Synthesis Engine (R.I.S.E.) Gallery Graphics Areas – Rendering

13 Henrik Wann Jensen - Global Illumination Image Gallery Graphics Areas – Rendering

14 The Aggregated Teapot - Andy Lomas Graphics Areas – Rendering

15 cgkit tutorial - Matthias Baas Graphics Areas – Animation

• Creating an illusion of motion through a sequence of images – Time as a key issue, not normally dealt with in basic modeling and rendering

16 Graphics Areas – Animation

Lucasfilm, The Adventures of André and Wally B.

Disney Research, Content Retargetting Using Parameter Parallel Facial Layers Graphics Areas - Imaging

18 Graphics Areas - Imaging

19 Graphics Areas - Imaging source/destination

sources destinations cloning seamless cloning color transfer monochrome transfer

Figure 5: Monochrome transfer. In some cases, such as texture transfer, the part of the source color remaining after seamless cloning might be undesirable. This is ﬁxed by turning the source image monochrome beforehand.

Figs. 6 and 7.

cloning seamless cloning sources/destinations

Figure 3: Insertion. The power of the method is fully expressed20 when inserting objects with complex outlines into a new back- ground. Because of the drastic differences between the source and the destination, standard image cloning cannot be used in this case. (a) color-based cutout and paste (b) seamless cloning

Figure 6: Inserting objects with holes. (a) The classic method, color-based selection and alpha masking might be time consuming and often leaves an undesirable halo; (b-c) seamless cloning, even averaged with the original image, is not effective; (d) mixed seamless cloning based on a loose selection proves effective. source/destination cloning seamless cloning

swapped textures source destination Figure 4: Feature exchange. Seamless cloning allows the user to replace easily certain features of one object by alternative features. In the second example of texture swapping multiple broad strokes (not shown) were used. Figure 7: Inserting transparent objects. Mixed seamless cloning facilitates the transfer of partly transparent objects, such as the rain- bow in this example. The non-linear mixing of gradient fields picks The discrete counterpart of this guidance field is: out whichever of source or destination structure is the more salient at each location. fp∗ fq∗ if fp∗ fq∗ > gp gq , vpq = − | − | | − | (13) gp gq otherwise, This mixed seamless cloning is also useful when adding one ob- ! − ject from a source image very close to another object in the desti- for all p,q . The effect of this guidance field is demonstrated in nation image, see Fig. 8. ⟨ ⟩

316 Graphics Areas – User Interaction

• Deals with the interface between input devices, the application, and feedback to the user in imagery and other sensory feedback

21 iPhone - Apple Graphics Areas – Virtual Reality

• Immersion of user into a 3D virtual world – Typically involves stereo graphics – Response to head motion – Force feedback

22 Oculus Rift DK2 Graphics Areas – Image Processing

• Manipulation of 2D images – Interpolation – Filters – Conversion

23 www.shadedrelief.com Graphics Areas – 3D Scanning

• Uses range-finding technology to create measured 3D models

Inventor Connections Major Applications

• Video Games • Cartoons • Film Special Effects • CAD/CAM • Simulation • Medical Imaging • Information Visualization

25 Applications – Video Games

• 3D modeling • 3D scanning • Rendering algorithms • User interaction • Force feedback • Motion capture • Graphics data structures • Etc...

26 Applications – Video Games

27 The Legend of Zelda: Twilight Princess - Nintendo Applications – Video Games

28 Kevin Durant at Electronic Arts Motion Capture Studio - AP / Richard Lam Applications – Video Games

29 Applications - Cartoons

• Often rendered from 3D models • Traditional 2D use backgrounds rendered from 3D models

30 Luxo Jr - Pixar Applications – Film Special Effects

• Almost all graphics technologies • Digital compositing to superimpose filmed foregrounds onto backgrounds • Foregrounds with 3D models

31 Applications – Film Special Effects

32 300 - Warner Bros. Pictures Applications – Film Special Effects

33 The Matrix - Warner Bros. Applications - CAD/CAM

• Used to model/design parts which directly guide the manufacturing process • Computer controlled milling devices

34 Applications - CAD/CAM

35 Applications - CAD/CAM

36 Applications – Simulation

• “Serious games” • Flight & driving simulators • Situations which are too dangerous to costly to perform directly

37 Applications – Simulation

38 Lander Simulation & Training Solutions, S.A. Applications – Simulation

39 Army Research Labs Applications – Simulation

40 United States Navy Applications – Medical Imaging

• Create meaningful images of scanned patient data • MRI/CT scans of density values • Large amounts of data – Very small test sets have 256 × 256 × 128 ≈ 8.4 million samples

41 Applications – Medical Imaging

42 MRbrain dataset - The Stanford volume data archive Applications – Medical Imaging

43 Levoy, M. 1998. Display of surfaces from volume data Applications – Visualization

• Understanding 3D data • Creates images of data which do not have a “natural” visual depiction • Finding patterns in data

44 Applications – Visualization

45 Applications – Visualization

46 munterbund.de Applications – Visualization

47 Robert J. Vanderbei Debugging

• “The Scientific Method” • Images as Coded Debugging Output • Set a trap • Visualization