Design of Animation Sequences
A key frame is a detailed drawing of the scene at a certain time in the animation sequence. Within each key frame, each object is positioned according to the time for that frame. Some key frames are chosen at extreme positions in the action; others are spaced so that the time interval between key frames is not too great. More key frames are specified for intricate motions than for simple, slowly varying motions.
一个关键帧是动画序列中特定时刻的一个场景的详细图示。在每一个关键帧中，每一个对象的位置依赖于该帧的时刻。选择某些关键帧作为行为的极端位置。另一些则以不太大的时间间隔进行安排。对于复杂的运动，要比简单的缓慢变化运动安排更多的关键帧。
In-betweens are the intermediate frames between the key frames. The number of in-betweens needed is determined by the media to be used to display the animation. Film requires 24 frames per second, and graphics terminals are refreshed at the rate of 30 to 60 frames per second. Typically, time intervals for the motion are set up so that there are from three to five in-betweens for each pair of key frames. Depending on the speed specified for the motion, some key frames can be duplicated. For a 1-minute film sequence with no duplication, we would need 1440 frames. With five in-betweens for each pair of key frames, we would need 288 key frames. If the motion is not too complicated, we could space the key frames a little farther apart.
插值帧是关键帧之间过渡的帧。插值帧的数量取决于用来显示动画的介质。电影胶片要求每秒24帧，而图形终端按每秒30到60帧来刷新。一般情况下，运动的时间间隔设定为每一对关键帧之间有3~5个插值帧。依赖于为运动指定的速度，有些关键帧可重复使用。一分钟没有重复的电影胶片需要1440帧。如果每两个关键帧之间有5个插值帧，则需要288幅关键帧。如果运动并不是很复杂，我们可以将关键帧安排得稀一点。
General Computer-Animation Functions
Some steps in the development of an animation sequence are well suited to computer solution, These include object manipulations and rendering, camera motions, and the generation of in-betweens. Animation packages, such as Wave-front, for example, provide special functions for designing the animation and processing individual objects.
Another typical function simulates camera movements. Standard motions are zooming, panning, and tilting. Finally, given the specification for the key frames, the in-betweens can be automatically generated.
通用计算机动画功能
开发动画序列中的某几步工作很适合计算机进行处理。其中包括对象管理和绘制、照相机运动和生成插值帧。动画软件包，如Wavefront，提供了设计动画和处理单个对象的专门功能。
另一种典型功能是模拟照相机的运动，标准的运动有拉镜头、摇镜头和倾斜。最后，给出对关键帧的描述，然后自动生成插值帧。
文章来源于领测软件测试网 https://www.ltesting.net/
