chapter five

Basic Computer Animation Techniques

syed ardi syed yahya kamal2011

chapter five

Principles of Keyframe Interpolation Creating in-between positions is still a

hallmark of animation. Using techniques called interpolation

computer animation software can create the in-between positions.

This is called keyframe interpolation, and it is an essential computer animation technique used in a myriad of ways to create sequences of still frames.

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Cont.. Keyframe interpolation calculates the

in-between frames by averaging the information specified in keyframes.

Interpolation techniques can be used to calculate the position of objects in space, as well as their shapes and other attributes.

The most common types of interpolation include linear and curve interpolation.

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Cont.. Establishing a keyframe is usually

done interactively, using an animation timeline that stores the position and duration of the different moments and actions being animated.

Interpolating keyframes allows us to control the time, or speed, that is takes to get from one keyframe to another and the rate of change between frame.

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Cont.. Interpolation is commonly expressed in

the form of a graph that shows the relation between time and the parameter being animated.

Time is usually represented by the horizontal axis and the parameter in question is usually represented by the vertical axis.

The slope of the path in the graph represents the speed or rate of change.

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Cont.. Interpolation graphs are generated

automatically by most computer animation software as soon as animator specifies the animation parameters on one or several objects in the scene.

It is usually possible to edit these graphs interactively.

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Linear Interpolation Linear interpolation is the simplest and

most straightforward computer animation technique for calculating in-between frames.

Linear interpolation simply averages the parameter in the keyframes and provides as many equally spaced in-between frames as needed.

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Cont.. Linear interpolation is based on

constant speeds between the keyframes.

Constant speed is represented by the straight lines in the graph.

Linear interpolations cannot handle subtle changes in speed because the in-between frames are created at equal intervals along the path.

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Curve Interpolation Also called interpolation ease, is a

techniques for calculating in-between frames that is more sophisticated than a linear interpolation.

Curved interpolation averages the parameter in the keyframes, taking into account the variations of speed over time, known as acceleration.

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Cont.. When curved interpolation is represented

in graphical form the increase in speed, also called an ease in, is represented by a line that curves up.

An ease out, or decrease in speed, is represented by a line that curves down.

Therefore, the distribution of in-between frames along the path depends on whether the rate of change increases or decreases.

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Getting Ready For Animate Choose Appropriate Motion

Audience learn a lot about the emotions and intentions of animated characters by the way they move.

Make sure that the motion applied to the models matches the dramatic purpose of the scene.

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Cont.. Avoid Still First Frames

One or several still frames at the beginning of an animated sequence usually look like a mistake, as if when the camera starts rolling before the actors are ready.

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Cont.. Preview the Motion

Virtually all computer animation programs allow for the creation of motion flipbooks that can be played back directly onto the computer screen.

Before digital flipbooks are available, motion test could only be previewed by recording each frame onto a videotape , and playing them back on videotape player.

Those days are fortunately gone

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Cont.. Check the Preference File

Setting the preferences for file including the animation rate of frames per second, the aspect ratio of the still image and whether to load external files.

This will affect the final look of the animation project.

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Cont.. Follow the Animatic or Storyboard

When animating it is important to stick to the directions specified in the animatic or storyboard because other individuals may be working at the same time on the same sequence as you are.

chapter five

End of Chapter 5syed ardi bin syed yahya kamal