Computer Animation

K Hoffman

Creating a Link Constraint key for bouncing ball

1. Complete exercise 10.4 Passing a Ball with Link Constraint
2. Open “BallBounceRoll.max file
3. Add Link Constraint to Ball at fr 0. Set Target to World
4. Create dummy around ball at fr 76
5. Select ball and create “Create Key” at fr 76
6. Delete ball position key at frame 100
7. Select ball and in the Link Constraint rollout select dummy as target at frame 76
8. Create Position key for dummy at frame 100
9. Create Rotation key for dummy at frame 100

Squash and stretch for Ball

1. Create an oblong plane surface in the Top Viewport
2. Create a sphere above the plane surface at a height equal to about 10 times the diameter of the ball.
3. Turn on Auto Key and move to frame 15
4. Place ball on plane.
5. Move to frame 30 and place ball at starting point.
6. Turn off Auto Key
7. Change Center of rotation so that pivot point of ball is on bottom edge.
8. Turn on Auto Key
9. At frame 7 stretch ball slightly with scale option on local Y axis
10. At frame 13 flatten ball slightly on Y axis
11. Turn off Auto Key
12. Copy stretch frame to frame 22
13. Copy squash frame to frame 17
14. Open Track View Dope Sheet and delete X and Y position frames
15. Play animation and adjust tangent curve so ball moves slower near top and faster near plane surface.
16. On Dope Sheet select “Z Position” and “Scale.”
17. Open Out-of-Range Types and select Loop option.
18. Select trajectories button in Motion panel
19. Turn on Auto Key and go to frame 100.
20. Drag ball on X axis to the right end of the plane
21. Turn off Auto Key and play animation.