Define computer animation. Explain the stages to design animation sequences.

5.A] Define computer animation. Explain the stages to design animation sequences.

Answer:

• Computer animation generally refers to any time sequence of visual changes in a picture.
• In addition to changing object positions using translations or rotations, a computer- generated animation could display time variations in object size, color, transparency, or surface texture.

Two basic methods for constructing a motion sequence are

1. real-time animation
   • In a real-time computer-animation, each stage of the sequence is viewed as it is created.
   • Thus the animation must be generated at a rate that is compatible with the constraints of the refresh rate.
2. frame-by-frame animation
   • For a frame-by-frame animation, each frame of the motion is separately generated and stored.
   • Later, the frames can be recorded on film, or they can be displayed consecutively on a video monitor in “real-time playback” mode.

Animation Sequence Design Steps:-

Storyboard Layout:

• Visual outline of the animation sequence.
• Includes rough sketches or a list of ideas representing key moments and transitions.
• Helps plan the overall flow and action of the animation.

Object Definitions:

• Define objects to be animated using basic shapes (e.g., splines, polygons).
• Specify movements and transformations for each object.
• Ensures accurate representation and movement of objects.

Key-Frame Specifications:

• Detailed drawings or representations of the scene at specific times.
• Capture critical moments and significant changes in the animation.
• Key frames are placed at extreme positions or major points, with more key frames for smooth, fast motions.

Generation of In-Between Frames:

• Frames between key frames that create smooth transitions.
• Number of in-betweens depends on media format (e.g., film needs 24 frames per second).
• Maintains smooth animation by filling gaps between key frames.
• Key frames may be duplicated based on motion speed to maintain the desired frame rate.

Additional Tasks:

• Synchronize with audio, such as background music, sound effects, or voiceovers.
• Ensures that the animation’s audio elements match the timing and action of the animation.

Raster Methods for Computer Animation

1. Creating Animation Sequences
   • Real-Time Animation: Simple animation sequences can be created in real-time by continuously updating and displaying frames. This involves generating each frame on the fly, ensuring that the animation appears smooth and continuous.
   • Frame-by-Frame Animation: Alternatively, frames can be created one at a time and saved to files. These frames can later be viewed sequentially or transferred to film for playback.
2. Displaying Animation
   • Sequential Frame Viewing: After creating the frames, they can be cycled through to display the animation. This method is often used for playback of pre-rendered sequences.
   • Real-Time Frame Generation: For continuous animation, frames must be generated quickly enough to maintain smooth motion. This requires efficient rendering techniques to keep up with the display refresh rate.
3. Double Buffering: Double buffering is a technique used to produce real-time animation by managing two buffers that handle the frame display and frame creation processes. This technique helps avoid flickering and ensures smooth transitions between frames.
   • Process:
     1. Initialize Buffers: Two buffers (front buffer and back buffer) are used. The front buffer is currently being displayed on the screen, while the back buffer is where the next frame is being constructed.
     2. Draw Frames: While the front buffer is being displayed, the next frame is drawn into the back buffer.
     3. Swap Buffers: Once the next frame is complete, the roles of the buffers are swapped. The back buffer becomes the front buffer (now displayed), and the former front buffer is now used for drawing the subsequent frame.
     4. Repeat: This process continues, allowing the animation to be displayed smoothly with minimal flicker.
   • Advantages:
     • Eliminates Flicker: By drawing to a back buffer while the front buffer is displayed, flickering that can occur when updating the display is reduced or eliminated.
     • Smooth Animation: Ensures that the transition between frames is smooth, as the entire frame is updated in one go.
   • Graphics Library Functions:
     • Activating Double Buffering: Libraries like OpenGL provide functions to enable double buffering. For example, in OpenGL, the glutInitDisplayMode(GLUT_DOUBLE) function activates double buffering.
     • Buffer Swapping: The glutSwapBuffers() function is used to swap the front and back buffers, making the newly drawn frame visible on the screen.