- Morph target animation
Morph target animation, per-vertex animation, shape interpolation, or blend shapes is a method of 3D computer animation used together with techniques such as skeletal animation. In a morph target animation, a "deformed" version of a mesh is stored as a series of vertex positions. In each key frame of an animation, the vertices are then interpolated between these stored positions.
The "morph target" is a deformed version of a shape. When applied to a human face, for example, the head is first modelled with a neutral expression and a "target deformation" is then created for each other expression. When the face is being animated, the animator can then smoothly morph (or "blend") between the base shape and one or several morph targets.  Typical examples of morph targets used in facial animation is a smiling mouth, a closed eye, and a raised eyebrow, but the technique can also be used to morph between, for example, Dr Jekyll and Mr Hyde.
When used for facial animation, these morph target are often referred to as "key poses". The interpolations between key poses when an animation is being rendered, are typically small and simple transformations of movement, rotation, and scale performed by the 3D software. 
Not all morph target animation has to be done by actually editing vertex positions. It is also possible to take vertex positions found in skeletal animation and then use those rendered as morph target animation.
An animation composed in one 3D application suite sometimes needs to be transferred to another, as for rendering. Because different 3D applications tend to implement bones and other special effects differently, the morph target technique is sometimes used to transfer animations between 3D applications to avoid export issues.
Benefits and drawbacks
There are advantages to using morph target animation over skeletal animation. The artist has more control over the movements because he or she can define the individual positions of the vertices within a keyframe, rather than being constrained by skeletons. This can be useful for animating cloth, skin, and facial expressions because it can be difficult to conform those things to the bones that are required for skeletal animation.
However, there are also disadvantages. Vertex animation is usually a lot more labour-intensive than skeletal animation because every vertex position must be manually manipulated and, for this reason, the number of pre-made target morphs is typically limited.  Also, in methods of rendering where vertices move from position to position during in-between frames, a distortion is created that does not happen when using skeletal animation. This is described by critics of the technique as looking "shaky". On the other hand, this distortion may be part of the desired "look".
- ^ a b c Liu, Chen (2006). "An Analysis of the Current and Future State of 3D Facial Animation Techniques and Systems". pp. 12–14. http://ir.lib.sfu.ca/bitstream/1892/11423/1/ETD4934.pdf. Retrieved January 2011.
- ^ Glanville, Steven (2006). "Anim8or Manual, Chapter 3 Object Editor". Anim8or. http://www.anim8or.com/manual/3_object_editor.html. Retrieved January 2011.
Animation topics By country Industry Works TechniquesOther methods Related topics
Wikimedia Foundation. 2010.
Look at other dictionaries:
Morph target animation — Este artículo o sección necesita referencias que aparezcan en una publicación acreditada, como revistas especializadas, monografías, prensa diaria o páginas de Internet fidedignas. Puedes añadirlas así o avisar … Wikipedia Español
Morph — may refer to: Contents 1 Astronomy 2 Biology 3 Computing 4 … Wikipedia
Animation — The bouncing ball animation (below) consists of these 6 frames. This animation moves at 10 frames per second. Animation is the rapid display of a sequence of images of 2 D or 3 D artwork or model positions in order to create an illusion of… … Wikipedia
Portal:Animation — Wikipedia portals: Culture Geography Health History Mathematics Natural sciences People Philosophy Religion Society Technology … Wikipedia
Computer animation — Further information: Animation and Computer generated imagery An example of computer animation which is produced in the motion capture technique Computer animation is the process used for generating animated images by using computer… … Wikipedia
Modern animation in the United States — History of animation in the United States Animation in the United States during the silent era Golden Age of American animation … Wikipedia
Traditional animation — Digital ink redirects here. For the display technology, see electronic paper. Traditional animation, (or classical animation, cel animation, or hand drawn animation) is an animation technique where each frame is drawn by hand. The technique was… … Wikipedia
Clay animation — or claymation is one of many forms of stop motion animation. Each animated piece, either character or background, is deformable made of a malleable substance, usually Plasticine clay. Characters in the animated series From Il ich to Kuzmich … Wikipedia
Flash animation — Simple animation in Flash MX; a square moving across the screen in a motion tween, one of the basic functions of Flash. Onion skinning is used to show the apparent motion of the square. A Flash animation or Flash cartoon is an animated film which … Wikipedia
Chinese animation — Blue cat, a character from Hunan, China Chinese animation (simplified Chinese: 华人制动画; traditional Chinese: 華人製動畫; pinyin: Huárénzhì dònghuà) or Manhua Anime, in narrow sense, refers to … Wikipedia