10. Animation

All Past Paper Questions: https://docs.google.com/document/d/1osDm8ZWYpGqo4qsB4ioe_5NMqt8prnXxOrlloWsXQ6c/edit?usp=sharing

Audio

• bit-rate
  • changing bit-rate
    • Audio quality improves with increasing bit rate
      • 800 bit/s is minimum for speech to be recognised
      • 32 kbit/s — generally acceptable only for speech
      • 96 kbit/s — generally used for speech/low-quality streaming
      • 128 or 160 kbit/s — mid-range bit rate quality
      • 192 kbit/s — a commonly used high-quality bit rate
      • 320 kbit/s — highest bit rate level supported by the MP3 standard
    • lossy compression to reduce bit rate can introduce artefacts
      • caused by data/quantisation errors
    • distortion of sound
    • perceived/heard as 'bubbling'
    • stuttering/jerky/silences in sound.

Computer Animations

Key Frames

• why

  • to define start and end of movement of an object
  • to specify movement of objects
    • that the viewer will see
  • to define timing of movement
    • by position of key frame in sequence of frame

• property key frames

  • defines (one or more) properties of an object in a frame
    • (Objects properties)
    • can be edited (within a property key frame)
  • to create in-between (tween) frames without the need to draw each frame individually
  • used as 'roving' (property key frames)
  • ensures speed of motion is consistent between frames
    • (throughout a tween)
  • to adjust the speed of motion
    • at beginning and end of tween sequence so that it appears more realistic between frames/throughout a tween
  • to add properties of one object onto other
    • by copying property key frames in timelines

• how sequence of frames created

  • question 1

    • 
    • answer
      • Animator drew frames 1 and 5 and 8
      • Frame 8 created by flipping frame 1
      • These are used as key frames
      • Frame 1 was duplicated to create frames 2, 3 and 4
      • Frame 5 was duplicated to create frames 6 and 7
      • Key frames define the start and end point of transitions that can be used by a computer-based animation application
      • Tweening was used to create frames in between.

  • question 2

    • 
    • answer
      • Using the four frames as key frames
        • filling in of frames between frames 1, 2, 3 and 4
        • using variable frame frequency depending on content
        • fewer frames between frames 1 and 2 than e.g. between 2 and 3
        • as background is stationary then lower frame rate than foreground characters
      • May be low frame rate so makes motion jerky (+ unrealistic)
      • Need to add at least 8 frames in order to create smooth movement
      • Need to add enough frames so that frame rate is below 'flicker fusion' threshold
        • else movement will appear to flicker and illusion of movement is destroyed
      • Motion blurring of the figures between frames 1 and 2 etc.
        • can simulate faster movement.

Editing

• call animation

  • Background objects drawn on one cell and placed at bottom of stack of cells
  • Character to be moved drawn on transparent cell
    • placed on top of background and photographed
  • Character redrawn as moved (on transparent cell) and replaced
  • Re-photographed/digitised in next frame
  • Process repeated for subsequent frames.

• stop motion

  • Scene arranged and lighted
  • Camera app setup
  • Frame recorded
  • Frame checked for corrections
  • Frame deleted if not required
  • objects moved slightly and re-photographed into new frame
  • Use of 'onion-skinning'
    • faint outline of previous frame in app
    • to show placement of objects
  • Frames duplicated
  • to slow the motion down
  • e.g. when character changes direction suddenly.

• text animation

  • strokes
    • an outline around the text letters
    • animated to move around the letters
    • to fade in/out around the letters
    • to different formats/colours e.g. dotted/dashed/thickness
    • to different comer formats e.g. sharp/smooth/rounded
  • fill settings
    • changes the contents of the letter shapes
    • Change the colour of the letter/shape
    • gradients
      • types
        • (multicolour) colour gradients gradually change one colour into another
        • linear gradients change colour along a single axis (horizontal or vertical)
        • radial gradients change colour in an outwardfinward direction starting from/to a central focal point
      • direction/focal point of gradient can be changed.

Animations

Properties

• orientation

  • description 1
    • is a camera property that is set in a keyframe
    • Surface sets the target for the camera on the object surface
    • Provides a sense of gravity for the object
    • Space sets the target for the camera at the centre of the object.
  • description 2
    • Sets the x, y, and z rotation angles around a fixed point (the origin) in a layer
    • (Rotation) around the x-axis is the roll, yaw, angle.
    • (Rotation) around the y-axis is the inclination, pitch, angle.
    • (Rotation) around the z-axis is the azimuth, heading, angle.

• transparency

  • (Sets the visibility of the objects, so) other layers in the display can be seen underneath.
  • Can be set to different percentages (of transparency/opacity) to change the visibility of layers underneath
  • Adjusted in keyframes to affect following frames
  • Can be adjusted so that some colours are removed screen effects
  • Can set a 'transparency track' in keyframes so transparency/opacity percentage changes between keyframes.

• animation speed (in 24fps)

  • usually 24fps or 30fps
  • each frame
    • actions may need to be very active / fast
    • animation can include a flurry of acitivity
      • around the main object
    • can make very smooth animations
  • each two frames
    • animator only needs to draw on 12 fps, not 24fps
      • saves time
      • less animators needed
      • cheap
    • makes slow animations smoother to eye
    • less accuracy required
      • (than drawing on each frame)
    • animations appear more lively / active
  • each four frames
    • animation may appear jerky
    • flashing of objects (on/off)
    • objects move very fast

Techniques

• tweening
  • stuff
    • usues location points
    • changes motion by creating intermeddiate frame
    • requires establishment of keyframes
    • moves points of location of object to new points
      • morphing doesn't do it
• morphing
  • stuff
    • changes one object into different object
    • smooth
    • overlays grid on images & uses it to remap new image
• tweening vs morphing
  • similarities
    • can change shape of an object
    • motion of object
    • can change size / color / location

Dimentions

• 2D objects

  • drawn in 2 dimensional space
  • measured in 2 axes/height and width/H x W/X and Y axes
  • based on (concept of) frames//
  • appear flat
  • cannot appear to rotate through 360 degrees
  • are only viewed from one/front angle
  • are only lit from one/front angle
  • lack texture/solidity
  • cannot/are not realistic in live scenes
  • examples
    • use in social media sites
    • presentations

• 3D objects

  • in 3 dimensional space
  • measured in 3 axes/height, width and depth/H x W x D/X,Y and Z axes
  • can have (appearance of) volume/depth
  • based on (concept of) movement (of objects)
  • have (appearance of) rotating through 360 degrees
  • (appear to) be viewed from different camera angles
  • (appear to) be lit from different directions
  • (appear to) have texture/solidity
  • (appear to) be placed into live scenes/elements with more realistic appearance
  • examples
    • use in movies
    • cartoons
    • video games

Other

• image editing, when making movies
  • Add visual special effects/CGI (computer-generated imagery)
    • to video sequences
    • show stuff that cannot exist in reality
  • Colourising monochrome film stock to increase acceptability
  • Images can be improved
    • eg: color grading Images can remove/include objects Images of impossible objects/situations can be created Altering photographic images to enhance
    • sales of products (can mislead buyers)
    • appearance (can mislead fans)