3D Animation II:Character Animation

Announcement

• If you haven’t received your midterm and/or your paper draft, please see Garnet after class.

SL Game

• This week in lab - choose teams of 3, no repeats.

• Next week - present game proposal.

• In-class prototype.

Simplicity

• VectorPark

• Ze Frank’s Frog

Vectorpark

• Demo…• http://www.vectorpark.com/ball.html

– Attention

– Use of color

– Interactivity

Ze Frank’s Frog

• http://www.zefrank.com/frog/frog.html

How Animation Is Changing

• Twenty differences between traditional and interactive animation.

1. Emotion

Animator controls emotion exhibited by characters in each shot. Each action that a character takes is inextricably tied to an emotion.

Animator creates dynamic emotional ranges that are explored during game play based on a range factors. Emotions may be layered on top of actions, and controlled independently.

Linear Animation Interactive Animation

1. Emotion

Affective range of a wolf pup.

2. Transitions

Since sequence of events is fixed, transitions between small chunks of animation are under the control of the animator, and may be long or short.

Since sequence of events is variable, cycles must be kept short or they cause a character to take too long to switch to a different action.

Linear Animation Interactive Animation

2. Transitions

Transition happens because you change your mind. How does that make you feel?

STAND_CYCLE

WALK_CYCLEWALK_TO_STAND

STAND_TO_WALK

STAND WALK

3. Virtuosity

Animator may make “virtuosic” animation sequences that show off a character’s personality.

“Virtuosic” animations are easy to identify, and therefore look repetitive or broken if played more than once.

Linear Animation Interactive Animation

3. Virtuosity

Can you name obviously repeated actions from a game?

4. Inter-character Action

Two characters may be animated together.

Enabling two characters to engage in expressive close contact (fighting, affection, etc.) in a robust way is an unsolved problem.

Linear Animation Interactive Animation

4. Inter-character Action

Close contact is difficult.

How does SL solve this?

5. Collision Avoidance

Characters only run into each other when animator wants them to.

Characters may accidentally collide with other and with objects in their world. Characters need a mechanism for avoiding collisions dynamically and coping with them if they occur.

Linear Animation Interactive Animation

5. Collision Avoidance

Step forward, step back.

How does SL deal with collisions?

6. Cinematography, Part I (Different camera angles)

Cinematography is predictable, so animations only have to look good from one angle.

Cinematography is dynamic, so animations have to look good from any angle.

Linear Animation Interactive Animation

6. Cinematography, Part I (Different camera angles)

Same character, different views

7. Cinematography, Part II (Cheating)

Position, orientation, size and other features of cinematic elements may be adjusted (“cheated”) to make a scene look better.

Cheating is much more difficult, since it may compromise other networked views of the world, etc. and is therefore less feasible.

Linear Animation Interactive Animation

7. Cinematography, Part II (Cheating)

Curiously placed antenna

8. Cinematography, Part III (Interactivity & Expressiveness)

Characters faces are more important than the backs of their heads, because the face shows a lot of the emotion.

Leading characters are often facing away from the camera, so that players are able to see where the character is going while they are steering.

Linear Animation Interactive Animation

8. Cinematography, Part III (Interactivity & Expressiveness)

Front of head, back of head

9. Cinematography, Part IV (Lighting)

Lighting design may be tailored to specific characters, sets, etc.

Interactive lighting design is an open topic of research, and is computationally expensive.

Linear Animation Interactive Animation

9. Cinematography, Part IV (Lighting)

10. Compositing

Different layers are frequently combined using off-line (i.e., high quality) techniques.

Final pass must be rendered in real-time.

Linear Animation Interactive Animation

10. Compositing

Metal Gear Solid 3

11. Sound, Part I (Music and Sound Effects)

Music and sound effects may be integrated with images in a variety of ways for expressive intent.

Music and sound effects are tied to virtual places, objects and characters.

Linear Animation Interactive Animation

11. Sound, Part I (Music and Sound Effects)

How does SL use music?

12. Sound, Part II (Dialog)

Dialog is pre-recorded, and may be used to help guide the animation.

Characters frequently have a small number of speech acts, and may therefore be repetitive.

Linear Animation Interactive Animation

12. Sound, Part II (Dialog)

13. Humor

Comic timing is (relatively) easy.

Comic timing is hard.

Linear Animation Interactive Animation

13. Humor

Why is humor so difficult?

14. Time

Time is frequently lengthened, condensed or reversed by editor. Animator drives the story during production.

Time is largely continuous. Player contributes to driving the story by interacting.

Linear Animation Interactive Animation

14. Time

Why game characters always run.

What functions in SL help solve this?

15. Script

Script resembles a screenplay, with characters, dialogue, etc.

Script resembles a computer program, with loops, conditionals, etc.

Linear Animation Interactive Animation

15. Script

while (character does not have key)

say “You do not appear to have completed your quest.”

16. Narrative

There is one course of events.

The narrative paths may be different each time a player interacts.

Linear Animation Interactive Animation

16. Narrative

What happens when you give a player some control?

17. Resolution

Resolution of animation limited only by screen size and frames per second.

Resolution limited by processor, graphics card, etc., and may be different for different players.

Linear Animation Interactive Animation

17. Resolution

Doom II

18. Magnitude

Animated films range in length from a few seconds to a few hours.

Interactive experiences may last much longer, up to many hundreds of hours.

Linear Animation Interactive Animation

18. Magnitude

One hour of game play per dollar.

19. Production Components

Animators create and integrate various components into a single shot.

Animators produce a very large number of clips – short animation segments that need to adhere to rigid technical criteria.

Linear Animation Interactive Animation

19. Production Components

“Drowning in a sea of clips”

20. Data

If the animation looks good, it’s done.

If the animation looks good but the animation data isn’t clean, it’s not done.

Linear Animation Interactive Animation

20. Data

The trouble with rigging…

Where does the character live?

• In the animator’s head?

• In a computer program?

Walk Cycle Reading

• Forward and Inverse Kinematics– Benefits and drawbacks

If Time, Watch Balance Again

• And make a motor graph