Assignment #2: Bouncing Ball Obstacle Course

Assigned: Thursday, October 6th, 2016
Due: Thursday, October 13th @ 5:00 PM

Resources:

• Demo Outline
• Demo Notes
• Obstacle course and ball rig.
• Animation Exercises:
  1. Basic Animation Exercise
  2. Graph Editor Exercise
  3. Animation Principles
• Playblasting Tutorial

You will be animating a single bouncing ball with forward momentum from an orthographic side view in Maya, using a planning sheet as a starting point. The ball falls into an obstacle course and eventually bounces/rolls to a halt. Before proceeding with the assignment, read through exercises 1 and 2 above. They will go over the basics of keyframe animation in Maya.

Part 1: Planning

Before heading into Maya, you will be constructing what is called a "planning sheet" (similar to the light vs heavy ball sketches you drew on the previous assignment). Planning sheets are a concept we will break apart and go into more detail on as the quarter progresses.

An image with the correct proportions of the obstacle course and ball can be found here. Print out the image and draw your poses directly on the sheet. You will see that the set consists of an obstacle course with an upper and lower level. Your ball must start where indicated with its initial momentum directed by the arrow. It can be treated as if it is a ping pong ball, bowling ball, or anything inbetween. However, whatever physical properties you choose the ball must not be overly squishy nor can it be floaty like a partially deflated balloon. At a minimum the ball should fall into the lower level of the obstacle course and react appropriately to anything it touches. Draw the ball up to the point at which it comes to a rest.

Scan in your planning sheet and save the file as bb_obstacle_course_planning_sheet.jpg.

Extra Credit: Add an obstacle and animate the ball contacting it (wall, ramp, bowling pin, etc). Any obstacle should be reactive! No extra characters or objects with momentum. And try not to go overboard with overly complicated models... the point is to focus on the motion itself!

 

Part 2: Animation

Setting Up

Open up the provided Maya file. You will see that the scene consists of both an obstacle course set and a ball rig. As with your planning sheet, the ball must begin its movement at the predefined starting position.

Animation Workflow

There are two controls on the provided rig: the "ball_anim" is for both movement and rotation, while the "squash_anim" allows you to modify the direction and magnitude of the squash and stretch independent of the ball's position and rotation. This means that it is much easier to add/adjust squash and stretch without negatively impacting other portions of your animation. You should always key both controls on a given frame, and not just one without the other.

Use your planning sheet as reference for a first pass of poses. As you work in Maya and play back your animation you may find that adjustments will need to be made. Ultimately, you are not required to follow the exact path and timing of the planning sheet. If you find that deviating will result in a better final product, by all means do so!

Think about the animation principles applied to your bouncing ball last week. Everything from the 2D space still applies to 3D, always have timing, spacing, arcs, and squash/stretch in the back of your mind as you set the poses. For this assignment you shouldn't see squash and stretch on the ball when playing at full speed but you should be still be able to feel it. Squash and stretch that spans too many frames will make the ball look like it is willing itself to jump - or just sticking to the ground. In general just use one or two frames of squash preceeded by one frame of stretch contacting the ground.

After you finish your animation you will need to export a movie for review. This playblasting tutorial will run through how to do this. Save the movie file as bb_obstacle_course.avi.

General Animation and Maya Tips

• Start with your "extreme" poses first! Get those right, then add breakdowns (poses further defining the motion between your extremes) as you need them.
• When defining poses for your ball you will want to key both controls on the same frame. If you stagger their keys (meaning, for example, that the ball_anim's keys don't line up with the squash_anim's keys), figuring out which key goes to which pose will become frustrating later and slow down your workflow. Keying all controls on the same frame is an important habit to start now, as the number of controls per rig will only increase from here. Think of each pose as if were a single sheet of paper with everything set in stone on that frame.
• Make sure keys don't land on partial frames (for example, frame 3.14). If this happens it is usually the result of key scaling. To fix partial framed keys, select all of the problem keys in the timeline, right-click hold on the selection, and choose "Snap".
• Try not to spend too much time in the Graph Editor. You will definitely want to do some touch-up in there eventually, but when you do focus on what your animation looks like. Don't put your effort into making completely symmetrical and nice curves. If a perfect looking motion graph doesn't make your animation look any better then there is no point. Sometimes you will just need to add more keys or breakdowns, and that is completely fine.
• Save iterations! You especially want to save an iteration when all of your key poses are set, before moving on to clean up the graph editor and adding in-betweens (basically another word for breakdowns).
• You may find the Editable Motion Trail useful for reference. Select the main ball anim then in the Animation menu set, go to Visualize → Create Editable Motion Trail. Remember to delete it when you're finished!
  
  
• The default playblast resolution is 1280x720, but for temporary playblasts it may be faster to lower the resolution to 640x360. The easiest way to do this is to keep the Scale at "0.50" in the Playblast Settings. Just be sure to change it back to the original resolution before turn in.
  
  

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:

Motion Check-In

• First iteration of the bouncing ball, stepped poses are fine (already playblasted!) Also this is when you need to indicate the type of ball you are animating (ping pong, bowling, rubber, etc.)

Part 1

• bb_obstacle_course_planning_sheet.jpg
• Comment on Catalyst what type of ball you are animating

Part 2

• bb_obstacle_course.ma
• bb_obstacle_course.avi
  • Final resolution should be 1280x720 of the render_cam orthographic side view.