Upcoming Deadlines

1. Pick up a clicker, find the right channel, and enter Student ID Upcoming Deadlines Fifth Homework (Video Analysis of a Jump) Due Thursday, Sept. 29th (In 2 weeks) 15 points (10 points if late) Sixth Homework (Stop-motion Animation) Due Thursday, Oct. 6th (In 3 weeks) 20 points (if late, 10 points) Bonus prize of 20 extra points to top three. For full schedule, visit course website: ArtPhysics123.pbworks.com

2. Tracker Exercise

3. Extra Credit Opportunity • Visit the R. Crumb “Genesis” exhibit (now through Sept.25) at the SJ Museum of Art http://www.sjmusart.org/ • Bring me proof of attendance (ticket stub, photos, etc.) by Sept. 26 for ten points of extra credit

4. Homework Assignment #5 In this assignment you’ll again use Tracker software to analyze the motion of a moving object from video reference. First, shoot some reference of yourself doing a running jump. Position your camera so that you're in frame the entire time that you're in the air. Stage the jump to be in profile. Shoot at least 5 takes, even if they are more or less the same.

5. Homework Assignment #5 Original Video Reference

6. Homework Assignment #5 Import your video reference into the Tracker software (as in previous homework). Track the center of your waistline or beltline, which is approximately the location of your center of gravity. Marking your position from the time you leave the ground until you’ve landed. After tracking your motion, upload the screen image from Tracker to your blog into a post called "Video analysis of path of action".

7. Homework Assignment #5 Straight Line Parabolic Path of Action Parabolic Curve

8. Homework Assignment #5 Finally, rewind your video to the first frame of your jump and from the "File" menu select ”Export -> Video Clip". Choose the export format (.avi, .mov, .gif, etc.) and click "Save As" to save the recording.

9. Homework Assignment #5 Video Reference with Tracking

10. Homework Assignment #5 Check that your saved movie has the track showing the path of action then put both clips (original and with tracking) in your blog post using YouTube or Vimeo. This assignment is due by 8am on Thursday, Sept. 29th (2 weeks from today). 15 points (10 points if late)

11. Assignment Checklist * Video clip has you running and jumping at least five times. * On one of the jumps you track the center of your body while you're in the air. * Show plots for both horizontal (x) position versus time and vertical (y) position versus time. * Graph of horizontal position versus time is roughly a straight line. * Graph of vertical position versus time is roughly a parabolic arc. * Post your screen shot in a blog entry entitled "Video analysis of path of action". * Post your original reference clip of your five jumps. * Also post a recorded Quicktime movie showing your path of action for one jump.

12. Activating your Clicker * Turn on your clicker. * Enter the channel number or letter for joining this class. Hit Enter/Send key. * Clicker should read AP123KF11 * Type in your student ID; hit Enter/Send. Clicker is now ready to use; leave it on. Hit any key to wake the clicker from sleep mode.

13. Survey Question • So far the pace of the class has been: • Too fast • A little fast • About right • A little slow • Too slow

14. When you want to throw a ball as far as possible, release it at and angle of_? • 15 degrees • 30 degrees • 45 degrees • 60 degrees • 90 degrees

15. “Shoot the Monkey” Rifle is aimed at monkey’s nose. Monkey lets go of the branch the moment he hears the gun fire. • Bullet hits the monkey: • Above the nose • On the nose • Below the nose

16. Tracking and Motion Graphs

17. Analyzing Video Reference Reference is not for rotoscoping (tracing images from a film) but to study the motion. We can also use video analysis tools to help us see the patterns of motion in a scene that we’ve filmed.

18. Graph of Ball Drop Heights Height Notice the shape of the curve made by the dots. This is a parabolic arc. Frames

19. Tracking a Jump StraightLine HorizontalMotion VerticalMotion Parabolic Arc

20. Motion Graphs In computer animation the timing and spacing of motion is often viewed using motion graphs, which can be manipulated in a graph editor. Position Frame

21. Autodesk Maya software Maya is one of the leading tools in computer animation. You will do two homework assignments near the end of the semester using Autodesk Maya.

22. Motion Graph for Uniform Motion The motion graph for uniform motion at a constant speed is a straight line. Position Frame

23. Motion Graphs in Maya Position Frame The motion graph for a ball drop looks something like this in Maya

24. Parabolic Arcs The motion graphs for a ball on a parabolic path of action. Vertical Horizontal Position Frame

25. Maya Demo for Bouncing Ball Let me demonstrate how to set up a simple bouncing ball in Autodesk Maya. Our animation will be of a ball that is 4 inches in diameter (2 inches in radius) The ball will fall from a height of 4 feet (48 inches). It takes ½ second (12 frames) to reach the ground. Use Fourth Down at Half Time

26. Maya Demo for Bouncing Ball Can add horizontal motion to the bouncing ball as well as bounces at decreasing height. A simple way to make parabolic arcs with apexes of decreasing height is to use the upper part of the previous arc.

27. Motion Capture & Tracking Motion capture is automated video tracking. Beowulf (2007) Data from sensor points can be used to create motion graphs in Maya.

28. Using Reference Wisely Artists know that reference is very important but they also recognize that they shouldn’t be slaves to their reference. Photo reference shot by Eakins Thomas Eakins,The Swimming Hole (c. 1884)

29. Using Physics Wisely Physics helps understand motion yet animators shouldn’t be slaves to it. The plane’s path of action feels like a roller coaster drop.

30. Review Question The motion graph for a ball drop, going from the apex until the ball just touches the ground, looks like: A) B) C) D)

31. Motion Graph of a Ball Drop D) Height Frames

32. Arcs in Animation

33. Disney’s Principles of Animation In their classic book, Disney Animation – The Illusion of Life, Frank Thomas and Olie Johnston list a set of basic principles for animation. • Squash & Stretch • Timing • Anticipation • Staging • Follow Through & Overlapping Action 6. Straight Ahead & Pose-to-Pose Action 7. Slow In and Slow Out 8. Arcs 9. Exaggeration 10. Secondary Action 11. Appeal

34. Disney’s Principles of Animation In their classic book, Disney Animation – The Illusion of Life, Frank Thomas and Olie Johnston list a set of basic principles for animation. We have already discussed several of these principles of animation, specifically: • Squash & Stretch • Timing • Anticipation • Staging • Follow Through & Overlapping Action 6. Straight Ahead & Pose-to-Pose Action 7. Slow In and Slow Out 8. Arcs 9. Exaggeration 10. Secondary Action 11. Appeal

35. Disney’s Principles of Animation In their classic book, Disney Animation – The Illusion of Life, Frank Thomas and Olie Johnston list a set of basic principles for animation. Today we will discuss arcs and how they relate to animated motion. • Squash & Stretch • Timing • Anticipation • Staging • Follow Through & Overlapping Action 6. Straight Ahead & Pose-to-Pose Action 7. Slow In and Slow Out 8. Arcs 9. Exaggeration 10. Secondary Action 11. Appeal

36. Arcs of Motion Motion usually follows an arc, which may be simple, like a circle, or very complex and irregular.

37. Importance of Arcs Disney animation legends Frank Thomas and Olie Johnston write: One of the major problems for the inbetweeners is that it is much more difficult to make a drawing on an arc. Drawings made as straight inbetweens completely kill the essence of the action. Right Wrong

38. Circular Arcs Circular arcs are common since motion is often around a fixed pivot point, such as a joint.

39. Speed in Circular Motion Rotational Speed: Revolutions per second Tangential Speed: Total distance per second Same Rotational Speed Different Tangential Speeds

40. Rolling & Slipping 1 2 3 4 5 6 7 ROLLING Rolling ball turns one revolution when it travels a distance equal to three times its diameter (actually 3.1416 diameter) 1 2 3 4 5 SLIPPING Slipping and rolling are both uniform in spacing and rotation.

41. Throwing Arm The longer the throwing arm, the greater the tangential speed so the farther it can throw. Tangential Speed x2 Sling lengthens the arm at almost no cost in the weight. Doubling the speedquadruples the range!

42. Timing on Circular Arcs A circular arc is a simple path of action but the timing may be complex and textured. • In this golf swing the motion: • Slows out (accelerates) to hit the ball • Uniform after the hit • Slows in as the swing finishes follow-through Slow in Uniform Slow out

43. Non-Uniform Circular Motion Two common types of motion on circular arcs that have non-uniform timing and spacing are: Exponential Spacing Pendulum Spacing Example:Tipping over Example:Stride inwalking

44. Pendulum Spacing A pendulum’s path of action is also a circular arc but the spacing is very different from the exponential spacing of tipping over.

45. Spacing & Timing in Swinging A pendulum will slow in and out as it swings back and forth, the same as a ball rolling in a half-pipe. Most of the texture in the timing is at the endpoints; the timing is even in the center.

46. Pencil Test Example http://www.youtube.com/watch?v=xuoJdNGxffU

47. Motion Graph for Pendulum The motion graph (angle vs. frame) shows that the timing is mostly textured (curves the most) at the apexes. #7 SLOW, again #1 Angle SLOW SLOW, again FAST FAST #4 Ball goes fastest around the bottom but the speed is almost constant. SLOW Frame

48. Uniform Rotation in Perspective The timing for uniform rotation has texture when seen in perspective. Half orbit Quarterorbit Rotation from key #1 to #5 in background takes twice as long as from #6 to #8 in foreground.

49. Swinging in Perspective Visually the timing has even more texture when the swing occurs in perspective.

50. Demo: Don’t Flinch Pendulum swings back and forth yet it doesn’t hit your face.