Computer video format depends on input and output devices for the motion video medium. The output of digitized motion video depends on the display device. Eg. Raster displays.
Video controller displays the image stored within the buffer store, accessing the memory through a separate access port as often because the raster scan rate dictates. The refresh of the display is the most important task. Due to flicker effect, the video controller cycles through frame buffer, one scan at a time typically at 60 times/second. For different color presentation on screen a color look up table (CLUT or LUT) is used.
Methods of controlling animation:
Controlling animation is independent of language used for describing it. Following techniques are used:
1) Full explicit control
The animator provides the description of everything that occurs in the animation. Description can be either by specifying simple changes such as scaling, transformation or by providing key frames. E.g.: BPOP system
2) Procedural control
Using the program to calculate the position, angle etc of the objects. In physical systems, the position of one object may influence the motion of another. Eg. Sutherland‘s sketch pad, Borning‘s Thing lab.
3) Constraint-based systems
Movements of object that are in contact with each other is constraint by physical laws. An animation can be specified by these constraints.
4) Tracking live action:
People or animals act out the parts of the characters in the animation The animation trace out the characters.
5) Kinematics and Dynamics:
Kinematics refers to position and velocity of points. E.g.: The ball is at origin at time t = 0. It moves with constant acceleration in the direction (1, 1, 5) thereafter. The final result of the animation is the sum of all the steps. If it does not fit, animator has to try again. This is known as forward kinematics. Inverse Kinematics (IK) is concerned with moving a skeleton form one pose to another.The animator specifies the desired position of the tip effecter; the IK algorithm will calculate the joint position, angle etc.
Dynamics takes into consideration the physical laws that govern the masses and forces functioning on the objects.. Example: The ball is at the origin at time t=0 second. It has the mass of 200 grams. The force of gravity acts on it.
Difference between animation and video
• Animation is often employed in those instances where video graphy isn't possible.
• Animation can better illustrate concept than video.
• Example- Earth is revolving around its axis cannot be video graphed but can show through animation.