https://www.stalliongaming.com/blog/knowing-keyframe-animation-and-using-it-in-videos/

Keyframe animation – Adobe After Effects

In media production, a key frame or Keyframe Animation may be a location on a timeline which marks the start or end of a transition. It holds special information that defines where a transition should start or stop. The intermediate frames are interpolated over time between those definitions to make the illusion of motion. In computer animation, like 3D animation or non-linear video editing, this interpolation is performed mathematically by the CPU.
In the following screenshot from Adobe After Effects, the keyframes are highlighted with red arrows. Each of the keyframes defines an edge of the animated logo (first on the left, then one second afterward the right). When the Keyframe Animation is played, the brand transitions smoothly from the beginning position to the top position.
Key frames are often utilized in any time-based media production process where transitions are defined, including audio production and high-end digital video compression.
The industry of computer animation has changed the look of television, feature films and video. Street explains, “The industry of computer animation is only twenty five years old. 1×1 that time, artist and scientist have moved from rudimentary ‘flying Iogos to the seemingly human move-characters.” It has grown since long time ago from a highly experimental work done by the scientists and engineers. Nowadays,wit h the increasing ability to produce computer animation at an acceptable cost and speed,. The role of computer animation is not only limited to the entertainment. It is widely used for web ontents, architectural simulation, virtual reality, flight simulation, military, medical, gaming industry and archaeology. Computer animation can be achieved in many ways such as.scripting systems, keyframing, behavioural animation and procedural animatio? Keyframing is one of the methods to produce animation, it is the main concept of computer animation. Mealing describes,”A more complicated motion can usually be decomposed into shorter sections, between the extremes of which, further positions are often interpolated.This incremental change from one keyframe to another is known as ‘in-betweening.
Keyframe Animation is simpler to try to to than Skeletal Animation. this system is employed when skeletal animation isn’t appropriate for instance , once you want to deform a mesh in some radical way. The downside is that keyframe animation can consume tons of VBO space.
The concept is that the following. you’ve got snapshots of a mesh with different poses. These snapshots are called the keyframes. As time passes, you compute the “current frame” using the old vertex position and newer vertex position. you’d even have to compute the normals. Texcoords don’t change. If you’ve got tangent vectors, you’ve got to compute these also . The indices never change between keyframes. the amount of triangles never change between keyframes. the amount of vertices never change between keyframes.
The keyframes are then distributed in time according to the timing of the user’s input path. Keyframe Animation we’ve implemented the approach as a plugin to the AliasWavefront Maya modeling and animation package. We demonstrate the approach on several example scenes and discuss its strengths and limitations.
A keyframe may be a timeline mark that records the position, scale, rotation, and opacity of an object at a selected frame of the scene.