CSC 8610 & 5930 Multimedia Technology Lecture 7 Animation Techniques

2 Today in class (4/16) 6:15Recap, Reminders 6:20Project discussion 6:45Lecture – Animation 7:30Break 7:45Lecture - Animation (cont’d) 9:00Wrap

3 ANIMATION TECHNIQUES

4 Animation Like video A sequence of images – Create illusion of movement when played in succession Commonly used in multimedia projects

5 Creating Animation Video editing programs Multimedia authoring programs: – Adobe Flash, Adobe Director – Often frame-based

6 Frame-based Animation sequence is created as a sequence of frames Usually on a timeline

7 What a Timeline Look Like in Adobe Flash Frame numbers A layer with a seqence of frames

8 Types of Techniques to Create Animation in Multimedia Authoring Program Frame-by-frame Tweening Scripting

9 FRAME BY FRAME

10 Frame-by-Frame By explicitly placing different visual content for each frame Each frame is a keyframe. Like flipbook animation “Flip Book Animation 1” “Flip Book Animation 2”

11 Keyframe A frame in which the content is explicitly specified. Different from a frame in which the content is interpolated between frames.

12 Frame-by-Frame Example Frame:

13 Frame-by-Frame Example Frame 1 Frame 2 Frame 3 Frame 4 Frame 5 Frame 6 Frame 7 Frame 8 Frame 9 Animation playing 2 fps

14 More Examples Post-It Note Animations How to Create Walking Animation

15 TWEENED ANIMATION

16 Tweened Animation Content in frames between 2 keyframes is interpolated These interpolated frames are called in-between frames.

17 What Does Interpolation Mean? Example: Suppose a bird in the first keyframe (frame 1) is at x = 11 and at x = 20 in the second keyframe (frame 10). Linear interpolation of the bird's x will make the bird at: – x = 12 in frame 2 – x = 13 in frame 3 – x = 14 in frame 4 –... and so forth

18 Continuing with the Bird Example In tweened animation, – what you need to do: create 2 keyframes: frames 1 and 10 only explicitly place the bird at x=11 in frame 1 and x=20 in frame – what the computer do for you: place the bird at x=12 in frame 2 place the bird at x=13 in frame 3... place the bird at x=19 in frame 9

19 Example of Bird Tweening Position Frame 1 Frame 2 Frame 3 Frame 4 Frame 5 Frame 6 Frame 7 Frame 8 Frame 9 Animation playing 2 fps

20 What can be tweened? Position (shown in the bird example) Rotation Size Color Opacity Shape

21 Example of Shape Tweened Bird Frame 1 Frame 10 Frame 20 Frame 30 Frame 40 Frame 50 Frame 60 Frame 70 Frame 80 Animation playing 30 fps

22 Example of Shape Tweened Bird Position (tweened) Rotation Size (tweened) Color Opacity (tweened) Shape (tweened) Animation playing 30 fps

23 SCRIPTED ANIMATION

24 Examples of Scripted vs Timeline Creating Animated GIFs (timeline) Adobe Flash with Tweening (scripted) PowerPoint animation (scripted)

25 Animation by Scripting/Programming Does not rely on a sequence of frames on timeline Dynamic: – Animation can be programmed to respond to the user's interaction – Animation can be different in a different play through

26 Frame-by-Frame vs. Tweened vs. Scripted Frame-by-FrameTweenedScripted Rely on a fixed sequence of visual content on timeline Always same animation every time you play Dynamic and interactive Require scripting

27 Frame-by-Frame vs. Tweened vs. Scripted Frame-by-FrameTweenedScripted Relative work in general required in creating the visual content longestshortest Choice of animation involving complex or organic motion such as walking and dancing may be Choice of animation involving continuous motion that can be interpolated

28 Animation Frame Size Width and height of the animation In multimedia authoring programs, such as Adobe Flash and Director: – determined by the stage dimension – also in pixels

29 Animation Frame Rate Playback speed of the animation In frames per second (fps) Too low: choppy Too high: choppy if the computer is not fast enough to process and display the frames

30 Animation Frame Rate Setting in Multimedia Authoring Programs Maximum rate The playback will: – not exceed the frame rate setting – not gurantee to maintain the frame rate (slower computer may play at frame rate lower than the setting)

31 Adjusting Speed of a Frame-based Animation Suppose you have a frame-based animation and want to change its playback speed. General Strategy: Avoid eliminating frames if possible

32 Adjusting Speed of a Frame-based Animation To speed up: – Increase frame rate if possible and keep the number of frames (preferred) – Keep the frame rate but reduce the number of frames (not preferred) To slow down: – Keep frame rate but add more frames (preferred) – Reduce frame rate but keep the number of frames

33 Example of Adjusting Speed Frame 1 Frame 2 Frame 3 Frame 4 Frame 5 Suppose you have this 5-frame animation and you want to slow it down.

34 Example of Adjusting Speed Suppose you have this 5-frame animation and you want to slow it down. If you reduce the frame rate and keep the same frame number:

35 Example of Adjusting Speed Suppose you have this 5-frame animation and you want to slow it down. If you reduce frame rate and keep the same frame number: If you keep the frame rate and add more frames:

36 Broader Context and Application Imagine – from Pencils to Pixels History of Computer Animation (2 parts) Torsten Reil builds better animations (TED Talk) David Bolinsky animates a cell (TED Talk)