FK (Forward Kinematics)
Forward Kinematics means your character rig will follow the hierarchal chain. This means more control over your chain, but also means you’d need to position each joint in your chain independently of each other. For example, with FK if you positioned the character’s hand the rest of the arm wouldn’t follow like it does with IK. Instead you would need to position each joint independently, starting with the upper arm, the elbow and then the wrist. This obviously takes more time than IK, but can give the animator much more control of the poses. Most times riggers will incorporate both FK and IK into the rig to meet the animator’s needs.
IK (Inverse Kinematics)
Inverse Kinematics means that the child node within your rig’s hierarchy can influence the movement of its parents. For ex ample, if you use IK for your character’s arm you can position your character’s hand and the rest of the arm chain will be calculated. This allows the animator to animate independently of the chain’s hierarchy. Because of this IK is great when needing to have a character’s arm stay planted on something. For example, pushing against a wall or swinging on a bar.
Fabrik for three.js
An implementation of FABRIK (Forward And Backward Inverse Kinematics) aside a little threejs library intended to provide easy three dimensional inverse kinematics for threejs and beyond. It can be used with IK chains of any length your computer can handle.
Github
CCDIKSolver.js = @Mugen87 comments above as well
- https://threejs.org/docs/#examples/zh/animations/CCDIKSolver
- https://github.com/mrdoob/three.js/blob/4930ea1ff67f0a349b9fa5b225a21069703bb7c9/examples/js/animation/CCDIKSolver.js
Using Kinect v2 jointOrientations along with Three.js skinnedMesh
https://social.msdn.microsoft.com/Forums/SECURITY/en-US/3f9e03b4-2670-41b5-9a91-2b72c77fe843/using-kinect-v2-jointorientations-along-with-threejs-skinnedmesh?forum=kinectv2sdk
https://www.openprocessing.org/sketch/607042
https://www.openprocessing.org/sketch/629151
fullik
http://lo-th.github.io/fullik/#3D_demo_0
Github
THREE.IK
https://jsantell.github.io/THREE.IK/
https://jsantell.github.io/THREE.IK/examples/#multi-effector
Github
matter.js
https://brm.io/matter-js/demo/#chains
Github
Analytic Two-Bone IK in 2D
Article
http://www.ryanjuckett.com/programming/analytic-two-bone-ik-in-2d/
Codepen
https://codepen.io/ge1doot/pres/zGywYw
jsfiddle
https://jsfiddle.net/satori99/pay0oqcd/
References