The Classic Ball Bounce Assignment 1 Dena Eber
Due Tuesday, September 10 Playblast
of Ball Bounce Animation
For Thursday, August 29
Bring an assortment of balls to class, rubber balls,
deflated balls, superballs, etc.
Review the following urls:
For Conceptual Help, See:
ballbounce physics 1
ballbounce physics 2
Ball Bounce Example:
least 2 balls, with different characteristics must be used.
of the real-world and of physics apply. Balls may not sprout wings, morph
into pacmen, or become autonomous characters.
must effect at least two other objects (not counting the walls and floors)
In Class Exercise:
The Classic Ball bounce:
- Make plane and ball
- Scale Plane and position Ball on far left of plane
- Group Ball to itself 3 times
- Name each Node in the Outliner (order is important)
- Modify -> Center Pivot for each group node
- In Channels set key on Translate X on the TransBall
Group on Frame 1
- Frame 60 move ball to other end of plane and set key
on X on TransBall
- Move to Frame 30 and set key frame
- Frame 1, 30, and 60 set key on TransBall Y(with
Ball on floor)
- Frame 15 and Frame 45 set key on Y with Ball up in
In Graph Editor:
- Select View->Frame All
- Select all bottom keyframes on the Y curve
- Break the tangents (Keys->Break) and Free the
weight (Keys->Free Tangent)
- Adjust Tangents so the ball hits the ground fast (MM
- Make sure second bounce is not as high as first
- Edit -> Copy the Frame 30 Translate X key
- Go to frame 31 in Timeline, return to Graph Editor,
and select Edit->Paste
- Go to frame 29 in Timeline, return to Graph Editor,
and select Edi->Paste
- In the Graph Editor, copy Value in 2nd Stats Box,
frame 29, into 2nd Stats Boxes
- For frames 30 and 31.
- Marque-Select keyframes 29,30 and 31 for the
- Go to Tangent -> In Tangent Linear.
In the Outliner:
- Select the Scale Node and move Pivot to the bottom of
the ball (INSERT (HOME on Mac) key ON then OFF)
- At Frame 15, Select All Three ScaleBall Nodes in Channel
Box, RMB and Key Selected
- Repeat above step for frame 45.
- At Frame 1 scale the ball down on Y and set key on
ScaleBall on the Y.
- MMB Drag to Frame 30 in Timeline, and set Key,
repeat for Frame 60.
- At Frames 5, 29, 35, and 59 scale the ball to 1 and
set keys on XYZ. (Easiest to set first)
- One, then MMB Drag in Timeline to next and set key.
Frame 1, 30 and 60 adjust the X and Z scaling to maintain equal volume and
set keys on scale X and Z
Rotate the Ball:
- See if you can get the ball to Rotate using the
RotateBall Node (only two key frames are needed)
- Make the ball bounce in half the time –
- Shift select the 3 nodes in the Outliner
Stretching key frames - scaling
In Graph Editor:
- Select All the Nodes in the Outliner
- In the Graph Editor - View Frame All
- Select All nodes
- Edit ->Scale Options
- Select Start-End method, enter in New Start/End
Times, hit Enter
- Click Scale Keys
- Remember to change the end time on the time slider
Problems for you to solve:
- Ball should stop rotation when it touches the
ground. Can you fix it?
- Ball’s rotation rate would decrease, can you
- Balls with different properties will bounce
differently, use different kinds of balls.