Tracker video analysis of falling

The image below shows the track of the falling ball, as obtained using the Tracker software.

The plot on the upper left is the horizontal position versus time. The graph should be a flat line because the ball does not move left-to-right but it's hard to mark the exact position so the graph shows some random variation.

The lower plot of the vertical position versus time is more interesting. Notice that this plot is a parabolic arc. There are about 16 frames from apex to impact and the 8th frame (half way down in time) is about a quarter of the distance from the apex to the ground. The frame rate in this clip is 30 fps so it takes just over a half second for the center of the ball to fall a height of about five feet (Corey Tom, who is dropping the ball, is 5 foot 9 inches tall).

Here are some examples from last semester:

http://samcriner.blogspot.com/2009/09/tracker-video-analysis-of-falling.html

http://edwardsartphysics123.blogspot.com/2009/09/tracker-video-analysis-of-falling.html

http://daytonalhazenskuse.blogspot.com/2009/09/tracker-video-analysis.html

http://kimknollanimationphysics.blogspot.com/2009/09/tracker-video-analysis-of-falling.html

Video Reference

Here is the video reference for a falling object (as dropped by SJSU's own Corey Tom). This reference was shot using a Sony HD digital camcorder and recorded at 30 frames per second.

Mini-Portfolio

Here are some examples of the "Mini-Portfolio" assignment (Homework #2):

http://christybecker.blogspot.com/2009/09/mini-portfolio.html
http://ryancanimation.blogspot.com/2009_08_01_archive.html
http://clamphysics123.blogspot.com/2009_08_01_archive.html
http://miyukianimationphysics123.blogspot.com/2009/08/mini-portfolio.html
http://artphysics123.blogspot.com/2009_05_31_archive.html

Spring Semester 2010

If you are reading this blog then you're probably enrolled in Physics of Animation (Art / Physics 123). This blog is primarily used to post examples to help you with your homework assignments, which you'll be posting on blogs of your own. Most of the information you'll need about the course is found on the course website, http://artphysics123.pbworks.com/.

Your first homework assignment for the course will be to set up a blog of your own, which you'll use to post homework assignments and term papers. You'll find more info on this first homework assignment here.
The earlier posts on this blog are from the Fall 2009 semester; the course will be similar but not quite the same this semester. Nevertheless, the postings from last semester will give you a general idea of the kinds of assignments you'll be doing.
 
See you in class!   Alej Garcia

Stereo 3D photo

Below are some examples of stereo 3D photos, such as what you'd create for the extra credit assignment. This is my (messy) office seen as a green/magenta anaglyph image and as a red/cyan anaglyph image. See the course website for instructions on how to create such images in Photoshop.

Top Three Stop-Motion Animations

The comments below are from stop-motion animator, Michael Stevenson, who was kind enough to serve as special guest judge for the last homework assignment.

It was a tough choice, but here's my top three:

Cat & Dog clay animation

Miyuki Maruyama

http://miyukianimationphysics123.blogspot.com/

This is a great example of taking a few simple motions - head turn, mouth open/close, and a tail wag - and infusing them with life through carefully planned timing. There's a very good use of holds - the characters' motives would be unclear and the humor would fall flat if the animation was driven forward at an even pace, but the characters' reactions are given plenty of room to breathe.

There are a lot of nice touches that help make the characters feel alive: eye blinks, turning the head before the eyes, reaction delays that imply an inner thought process, and so on. Great work.

Dance video group project

Chris Lam, Astro Leon-Jhong, Joe Tirasuwan, Marleah Edwards

http://clamphysics123.blogspot.com/

The ease in/out in this animation helps the dance moves to feel fluid without becoming slow or floaty. There's a nice snappiness to the motion, particularly in the shots of the police figure, that can be tough to capture in stop motion. The shot of the Gundam has a fun bit of overlapping action when the feet rebound up into frame - it really helps sell it. Overall a very nice piece.

Mannequin worship

Sam Debey

http://samdebey.blogspot.com/

Great concept! The motion is quite fluid, and the loop point is hidden well. There's a nice and subtle whip action going on in the spine, and the overlapping action is well-integrated. My only suggestion would be to add a bit more anticipation (perhaps even just a single frame) to the apex of the swing, but it's very solid as-is.

Stop-Motion Animation

Below is a stop-motion animation of a walk cycle created by Corey Tom. Note that this animation is composed of only about a dozen individual images, repeated over and over.