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Transcript of Upcoming Deadlines
Upcoming DeadlinesFifth 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.comPick up a clicker, find the right channel, and enter Student ID1Tracker Exercise
Extra Credit OpportunityVisit 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
Homework Assignment #5In this assignment youll 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.4Homework Assignment #5Original Video Reference
5Homework Assignment #5Import 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 youve landed.After tracking your motion, upload the screen image from Tracker to your blog into a post called "Video analysis of path of action".6Homework Assignment #5
ParabolicPath of ActionStraight LineParabolic Curve7Homework Assignment #5Finally, 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. 8
Homework Assignment #5Video Reference with Tracking9Homework Assignment #5Check 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)10Assignment 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.11Activating 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.12Survey QuestionSo far the pace of the class has been:
Too fastA little fastAbout rightA little slowToo slow
13When you want to throw a ball as far as possible, release it at and angle of_?15 degrees30 degrees45 degrees60 degrees90 degrees
Shoot the Monkey
Monkey lets go of the branch the moment he hears the gun fire.Rifle is aimed at monkeys nose.Bullet hits the monkey:Above the noseOn the noseBelow the nose
15Tracking and Motion Graphs
16Analyzing Video ReferenceReference 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 weve filmed.17Graph of Ball Drop Heights
FramesHeightNotice the shape of the curve made by the dots. This is a parabolic arc.18Tracking a JumpHorizontalMotionVerticalMotion
Parabolic ArcStraightLine19Motion GraphsIn computer animation the timing and spacing of motion is often viewed using motion graphs, which can be manipulated in a graph editor.PositionFrame20Autodesk Maya softwareMaya is one of the leading tools in computer animation.You will do two homework assignments near the end of the semester using Autodesk Maya.
21Motion Graph for Uniform Motion
The motion graph for uniform motion at a constant speed is a straight line.PositionFrame22Motion Graphs in MayaThe motion graph for a ball drop looks something like this in Maya
Parabolic ArcsThe motion graphs for a ball on a parabolic path of action.PositionFrameHorizontalVertical
24Maya Demo for Bouncing BallLet 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 second (12 frames) to reach the ground.
Use Fourth Down at Half Time25Maya Demo for Bouncing BallCan 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.26
Motion Capture & TrackingMotion capture is automated video tracking. Data from sensor points can be used to create motion graphs in Maya.
Beowulf (2007)27Using Reference WiselyArtists know that reference is very important but they also recognize that they shouldnt be slaves to their reference.
Thomas Eakins,The Swimming Hole (c. 1884)Photo reference shot by Eakins28
Physics helps understand motion yet animators shouldnt be slaves to it.Using Physics Wisely
The planes path of action feels like a roller coaster drop.29Review QuestionThe motion graph for a ball drop, going from the apex until the ball just touches the ground, looks like:A)B)C)D)
30Motion Graph of a Ball Drop
FramesHeightD)31Arcs in Animation
32Disneys Principles of AnimationIn their classic book, Disney Animation The Illusion of Life, Frank Thomas and Olie Johnston list a set of basic principles for animation.Squash & StretchTimingAnticipationStagingFollow Through & Overlapping Action6. Straight Ahead & Pose-to-Pose Action7.Slow In and Slow Out8.Arcs9.Exaggeration10.Secondary Action11.Appeal
33Disneys Principles of AnimationIn their classic book, Disney Animation The Illusion of Life, Frank Thomas and Olie Johnston list a set of basic principles for animation.Squash & StretchTimingAnticipationStagingFollow Through & Overlapping Action6. Straight Ahead & Pose-to-Pose Action7.Slow In and Slow Out8.Arcs9.Exaggeration10.Secondary Action11.Appeal
We have already discussed several of these principles of animation, specifically:
34Disneys Principles of AnimationIn their classic book, Disney Animation The Illusion of Life, Frank Thomas and Olie Johnston list a set of basic principles for animation.Squash & StretchTimingAnticipationStagingFollow Through & Overlapping Action6. Straight Ahead & Pose-to-Pose Action7.Slow In and Slow Out8.Arcs9.Exaggeration10.Secondary Action11.Appeal
Today we will discuss arcs and how they relate to animated motion.
35Arcs of Motion
Motion usually follows an arc, which may be simple, like a circle, or very complex and irregular.36
Importance of ArcsOne 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.
Disney animation legends Frank Thomas and Olie Johnston write:WrongRight37Circular Arcs
Circular arcs are common since motion is often around a fixed pivot point, such as a joint.38Speed in Circular MotionRotational Speed: Revolutions per secondTangential Speed: Total distance per second
Same Rotational SpeedDifferent Tangential Speeds39
Rolling & Slipping1234567Rolling ball turns one revolution when it travels a distance equal to three times its diameter (actually 3.1416 diameter)ROLLING12345SLIPPINGSlipping and rolling are both uniform in spacing and rotation.40
Throwing ArmTangentialSpeedThe longer the throwing arm, the greater the tangential speed so the farther it can throw.Sling lengthens the arm at almost no cost in the weight.Doubling the speedquadruples the range!x241Timing on Circular ArcsIn this golf swing the motion: Slows out (accelerates) to hit the ball Uniform after the hit Slows in as the swing finishes follow-through
A circular arc is a simple path of action but the timing may be complex and textured.Slow outUniformSlow in42Non-Uniform Circular Motion
Two common types of motion on circular arcs that have non-uniform timing and spacing are:Exponential SpacingPendulum Spacing
Example:Stride inwalking43Pendulum Spacing
A pendulums path of action is also a circular arc but the spacing is very different from the exponential spacing of tipping over.44Spacing & Timing in SwingingA 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.45Pencil Test Examplehttp://www.youtube.com/watch?v=xuoJdNGxffU
Motion Graph for PendulumThe motion graph (angle vs. frame) shows that the timing is mostly textured (curves the most) at the apexes.
FrameAngle#1#4#7FASTFASTSLOWSLOWSLOW,againSLOW,againBall goes fastest around the bottom but the speed is almost constant.47Uniform Rotation in PerspectiveThe timing for uniform rotation has texture when seen in perspective.