Editing Computer animation (section)

==3D computer animation==
[[File:Rendering Side-by-side.jpg|thumb|303x303px|A frame of animation before and after rendering]]

=== Overview ===
For 3D computer animations, objects (models) are built on the computer monitor (modeled) and 3D figures are rigged with a [[Skeletal animation|virtual skeleton]]. Then the limbs, eyes, mouth, clothes, etc. of the figure are moved by the animator on [[key frame]]s. Normally, the differences between key frames are drawn in a process known as [[Inbetweening|tweening]]. However, in 3D computer animation, this is done automatically, and is called [[interpolation]]. Finally, the animation is [[Rendering (computer graphics)|rendered]] and [[Compositing|composited]].

Before becoming a final product, 3D computer animations only exist as a series of moving shapes and systems within 3d software, and must be [[Rendering (computer graphics)|rendered]]. This can happen as a separate process for animations developed for movies and short films, or it can be done in real-time when animated for videogames. After an animation is rendered, it can be [[Compositing|composited]] into a final product.

=== Animation attributes ===
For 3D models, attributes can describe any characteristic of the object that can be animated. This includes transformation (movement from one point to another), scaling, rotation, and more complex attributes like blend shape progression (morphing from one shape to another). Each attribute gets a channel on which [[Key frame|keyframes]] can be set. These keyframes can be used in more complex ways such as animating in layers (combining multiple sets of key frame data), or keying control objects to deform or control other objects. For instance, a character's arms can have a skeleton applied, and the joints can have transformation and rotation keyframes set. The movement of the arm joints will then cause the arm shape to deform.

=== Interpolation ===
3D animation software interpolates between keyframes by generating a [[Spline (mathematics)|spline]] between keys plotted on a graph which represents the animation. Additionally, these splines can follow [[Bézier curve]]s to control how the spline curves relative to the keyframes. Using interpolation allows 3D animators to dynamically change animations without having to redo all the [[Inbetweening|in-between]] animation. This also allows the creation of complex movements such as ellipses with only a few keyframes. Lastly, interpolation allows the animator to change the framerate, timing, and even scale of the movements at any point in the animation process.

=== Procedural and node-based Animation ===
Another way to automate 3D animation is to use procedural tools such as 4D [[Perlin noise|noise]]. Noise is any algorithm that plots [[Pseudorandomness|pseudo-random values]] within a dimensional space.<ref>{{Cite web |title=The Book of Shaders |url=https://thebookofshaders.com/11/ |access-date=2024-05-22 |website=The Book of Shaders}}</ref> 4D noise can be used to do things like move a swarm of bees around; the first three dimensions correspond to the position of the bees in space, and the fourth is used to change the bee's position over time. Noise can also be used as a cheap replacement for [[simulation]]. For example, smoke and clouds can be animated using noise.

Node-based animation is useful for animating organic and chaotic shapes. By using nodes, an animator can build up a complex set of animation rules that can be applied either to many objects at once, or one very complex object. A good example of this would be setting the movement of particles to match the beat of a song.

=== Disciplines of 3D animation ===
There are many different disciplines of 3D animation, some of which include entirely separate artforms. For example, hair simulation for computer animated characters in and of itself is a career path which involves separate workflows,<ref>{{cite book | doi=10.1145/1401132.1401247 | chapter=Realistic hair simulation: Animation and rendering | title=ACM SIGGRAPH 2008 classes | date=2008 | last1=Bertails | first1=Florence | last2=Hadap | first2=Sunil | last3=Cani | first3=Marie-Paule | last4=Lin | first4=Ming | last5=Kim | first5=Tae-Yong | last6=Marschner | first6=Steve | last7=Ward | first7=Kelly | last8=Kačić-Alesić | first8=Zoran | pages=1–154 | isbn=978-1-4503-7845-1 | url=https://hal.inria.fr/inria-00520270/file/finalcoursenotes2008.pdf }}</ref> and different software and tools. The combination of all or some 3D computer animation disciplines is commonly referred to within the animation industry as the 3D animation pipeline.<ref>{{Cite web |last1=Naghdi |first1=Arash |last2=Adib |first2=Payam |last3=Adib |first3=Arash Naghdi and Payam |date=2021-05-10 |title=3D Animation Pipeline: A Start-to-Finish Guide (2023 update) |url=https://dreamfarmstudios.com/blog/3d-animation-pipeline/ |access-date=2024-05-21 |website=Dream Farm Studios |language=en-US}}</ref>
{| class="wikitable"
|+Examples of disciplines within the 3D animation pipeline
!Discipline
!Explanation
!Tools
!Examples
|-
|Face Rigging
|A facial rig is a rig that includes muscles, deformation, mesh displacement, and other techniques to enable the animation of facial expressions, and phonemes for lip syncing.
|Autodesk Maya, Blender
|In 'Avatar, Way of Water', WETA workshops meticulously designed the digital muscles in the faces of their characters so that their emotional range could be comparable to that of a human.<ref>{{Cite web |date=2022-12-21 |title=Exclusive: Joe Letteri Discusses Wētā FX's new Facial Pipeline on Avatar 2 - fxguide |url=https://www.fxguide.com/fxfeatured/exclusive-joe-letteri-discusses-weta-fxs-new-facial-pipeline-on-avatar-2/ |access-date=2024-05-21 |website=www.fxguide.com/ |language=en-US}}</ref>
|-
|Facial Animation
|This is the process of animating facial animations, [[Lip sync|lip-syncing]], and animating [[phoneme]] blend-shapes (shapes that the face morphs into)
|Autodesk Maya, Blender, Autodesk 3DS Max
|In Pixar's 'Turning Red', animators took influence from [[anime]] style facial expressions to inform their animation.<ref>{{Cite web |last=laurenlola |date=2022-03-09 |title="Turning Red" Animators on Anime Influences and Working with Domee Shi |url=https://caamedia.org/blog/2022/03/09/turning-red-animators-on-anime-influences-and-working-domee-shi/ |access-date=2024-05-22 |website=CAAM Home |language=en-US}}</ref>
|-
|Character Animation
|Specifically the animation of characters. 3D character animation is its own specialty do to the complexity required to animated dancing, running, fighting, or high fidelity motion such as playing basketball.
|Autodesk Maya, Blender
|Pixar's 'Incredibles' won the 2004 [[Visual Effects Society Award for Outstanding Animated Character in an Animated Feature]]
|-
|Cloth Simulation
|Cloth simulation is a subset of simulation but specifically for things like clothes. In modern 3D computer animation, cloth simulation is becoming more and more advanced and widely used.
|Houdini, Blender
|Pixar's 'Coco' advanced the use of high fidelity clothes by designing new tools to combine cloth simulation with character animation.<ref>{{cite book | chapter-url=https://doi.org/10.1145/3214745.3214801 | doi=10.1145/3214745.3214801 | chapter=Better collisions and faster cloth for Pixar's Coco | title=ACM SIGGRAPH 2018 Talks | date=2018 | last1=Eberle | first1=David | pages=1–2 | isbn=978-1-4503-5820-0 }}</ref>
|}