Assignment #1: Bouncing Ball Basics

Assigned: Friday, September 29th, 2017
Due: Friday, October 6th @ 10:00 AM

Resources:

Part 1: Light vs. Heavy Ball Sketches

On one sheet of paper, sketch out the poses of two different balls bouncing with forward momentum: a light ping pong ball and a heavy bowling ball. The two different motions should not overlap, but be easily comparable side-by-side or above-and-below. Draw enough frames such that we can see the balls roll to a stop. (You don't have to indicate the actual rotation in your drawings, but pay attention to the spacing.)

Assuming 24 frames per second, draw a pose every two frames. Make sure to emphasize the contrast between the different weights. Pay close attention to these principles:

  1. Timing. How does the rhythm of the ping pong ball bounces differ from the rhythm of the bowling ball bounces? Observe how these objects behave in reality. There are several ping pong balls available in the lab. Bowling balls are slightly harder to come by (if not a bit rough on the flooring), so check out video reference on the web. Here's one example.

  2. Spacing. When does the ball speed up? When does it slow down? This will also affect when squashing and stretching happens. Overlap drawings to signify deceleration and space them out for acceleration.

  3. Arcs. These should be included in every aspect of motion, as they serve to make animation more fluid and natural. Luckily, bouncing balls have built-in arcs. It may be helpful to sketch in the path of motion for each ball before drawing the poses.

  4. Squash and stretch. Keep in mind that you are animating a "normal" bouncing ball that doesn't have a mind of its own. Squash and stretch that is too extreme and that spans too many frames will make it look like the ball is willing itself to jump, and that's not what we want to see. A note for the future: you generally shouldn't see squash and stretch when your animation plays at full speed, but you should be able to feel it.

After you have finished your sketches scan them in. Check out this scanning tutorial to learn how to do this. Save your scan as bb_planning_sheet.jpg.

Part 2: 2D Animation in Flash

Animate a light ping pong ball and a heavy bowling ball bouncing side-by-side in 2D using Adobe Flash. Go through the 2D ball animation tutorial to accomplish this. The heavy ball should bounce and roll to a stop, but the light ball only needs to bounce while the heavy ball is still moving (with a minimum of three or four bounces).

Turn in both the Flash and AVI files specified under Part 2A and Part 2B.


Turn-in Checklist

You will be turning your files into Collect-It on Catalyst. Below is a check list of what you will be turning in and what those documents should be named:

Part 1

Part 2