( function () {
const _q = new THREE.Quaternion();
const _targetPos = new THREE.Vector3();
const _targetVec = new THREE.Vector3();
const _effectorPos = new THREE.Vector3();
const _effectorVec = new THREE.Vector3();
const _linkPos = new THREE.Vector3();
const _invLinkQ = new THREE.Quaternion();
const _linkScale = new THREE.Vector3();
const _axis = new THREE.Vector3();
const _vector = new THREE.Vector3();
const _matrix = new THREE.Matrix4();
/**
* CCD Algorithm
* - https://sites.google.com/site/auraliusproject/ccd-algorithm
*
* // ik parameter example
* //
* // target, effector, index in links are bone index in skeleton.bones.
* // the bones relation should be
* // <-- parent child -->
* // links[ n ], links[ n - 1 ], ..., links[ 0 ], effector
* iks = [ {
* target: 1,
* effector: 2,
* links: [ { index: 5, limitation: new THREE.Vector3( 1, 0, 0 ) }, { index: 4, enabled: false }, { index : 3 } ],
* iteration: 10,
* minAngle: 0.0,
* maxAngle: 1.0,
* } ];
*/
class CCDIKSolver {
/**
* @param {THREE.SkinnedMesh} mesh
* @param {Array<Object>} iks
*/
constructor( mesh, iks = [] ) {
this.mesh = mesh;
this.iks = iks;
this._valid();
}
/**
* Update all IK bones.
*
* @return {CCDIKSolver}
*/
update() {
const iks = this.iks;
for ( let i = 0, il = iks.length; i < il; i ++ ) {
this.updateOne( iks[ i ] );
}
return this;
}
/**
* Update one IK bone
*
* @param {Object} ik parameter
* @return {CCDIKSolver}
*/
updateOne( ik ) {
const bones = this.mesh.skeleton.bones; // for reference overhead reduction in loop
const math = Math;
const effector = bones[ ik.effector ];
const target = bones[ ik.target ]; // don't use getWorldPosition() here for the performance
// because it calls updateMatrixWorld( true ) inside.
_targetPos.setFromMatrixPosition( target.matrixWorld );
const links = ik.links;
const iteration = ik.iteration !== undefined ? ik.iteration : 1;
for ( let i = 0; i < iteration; i ++ ) {
let rotated = false;
for ( let j = 0, jl = links.length; j < jl; j ++ ) {
const link = bones[ links[ j ].index ]; // skip this link and following links.
// this skip is used for MMD performance optimization.
if ( links[ j ].enabled === false ) break;
const limitation = links[ j ].limitation;
const rotationMin = links[ j ].rotationMin;
const rotationMax = links[ j ].rotationMax; // don't use getWorldPosition/Quaternion() here for the performance
// because they call updateMatrixWorld( true ) inside.
link.matrixWorld.decompose( _linkPos, _invLinkQ, _linkScale );
_invLinkQ.invert();
_effectorPos.setFromMatrixPosition( effector.matrixWorld ); // work in link world
_effectorVec.subVectors( _effectorPos, _linkPos );
_effectorVec.applyQuaternion( _invLinkQ );
_effectorVec.normalize();
_targetVec.subVectors( _targetPos, _linkPos );
_targetVec.applyQuaternion( _invLinkQ );
_targetVec.normalize();
let angle = _targetVec.dot( _effectorVec );
if ( angle > 1.0 ) {
angle = 1.0;
} else if ( angle < - 1.0 ) {
angle = - 1.0;
}
angle = math.acos( angle ); // skip if changing angle is too small to prevent vibration of bone
if ( angle < 1e-5 ) continue;
if ( ik.minAngle !== undefined && angle < ik.minAngle ) {
angle = ik.minAngle;
}
if ( ik.maxAngle !== undefined && angle > ik.maxAngle ) {
angle = ik.maxAngle;
}
_axis.crossVectors( _effectorVec, _targetVec );
_axis.normalize();
_q.setFromAxisAngle( _axis, angle );
link.quaternion.multiply( _q ); // TODO: re-consider the limitation specification
if ( limitation !== undefined ) {
let c = link.quaternion.w;
if ( c > 1.0 ) c = 1.0;
const c2 = math.sqrt( 1 - c * c );
link.quaternion.set( limitation.x * c2, limitation.y * c2, limitation.z * c2, c );
}
if ( rotationMin !== undefined ) {
link.rotation.setFromVector3( _vector.setFromEuler( link.rotation ).max( rotationMin ) );
}
if ( rotationMax !== undefined ) {
link.rotation.setFromVector3( _vector.setFromEuler( link.rotation ).min( rotationMax ) );
}
link.updateMatrixWorld( true );
rotated = true;
}
if ( ! rotated ) break;
}
return this;
}
/**
* Creates Helper
*
* @return {CCDIKHelper}
*/
createHelper() {
return new CCDIKHelper( this.mesh, this.mesh.geometry.userData.MMD.iks );
} // private methods
_valid() {
const iks = this.iks;
const bones = this.mesh.skeleton.bones;
for ( let i = 0, il = iks.length; i < il; i ++ ) {
const ik = iks[ i ];
const effector = bones[ ik.effector ];
const links = ik.links;
let link0, link1;
link0 = effector;
for ( let j = 0, jl = links.length; j < jl; j ++ ) {
link1 = bones[ links[ j ].index ];
if ( link0.parent !== link1 ) {
console.warn( 'THREE.CCDIKSolver: bone ' + link0.name + ' is not the child of bone ' + link1.name );
}
link0 = link1;
}
}
}
}
function getPosition( bone, matrixWorldInv ) {
return _vector.setFromMatrixPosition( bone.matrixWorld ).applyMatrix4( matrixWorldInv );
}
function setPositionOfBoneToAttributeArray( array, index, bone, matrixWorldInv ) {
const v = getPosition( bone, matrixWorldInv );
array[ index * 3 + 0 ] = v.x;
array[ index * 3 + 1 ] = v.y;
array[ index * 3 + 2 ] = v.z;
}
/**
* Visualize IK bones
*
* @param {SkinnedMesh} mesh
* @param {Array<Object>} iks
*/
class CCDIKHelper extends THREE.Object3D {
constructor( mesh, iks = [] ) {
super();
this.root = mesh;
this.iks = iks;
this.matrix.copy( mesh.matrixWorld );
this.matrixAutoUpdate = false;
this.sphereGeometry = new THREE.SphereGeometry( 0.25, 16, 8 );
this.targetSphereMaterial = new THREE.MeshBasicMaterial( {
color: new THREE.Color( 0xff8888 ),
depthTest: false,
depthWrite: false,
transparent: true
} );
this.effectorSphereMaterial = new THREE.MeshBasicMaterial( {
color: new THREE.Color( 0x88ff88 ),
depthTest: false,
depthWrite: false,
transparent: true
} );
this.linkSphereMaterial = new THREE.MeshBasicMaterial( {
color: new THREE.Color( 0x8888ff ),
depthTest: false,
depthWrite: false,
transparent: true
} );
this.lineMaterial = new THREE.LineBasicMaterial( {
color: new THREE.Color( 0xff0000 ),
depthTest: false,
depthWrite: false,
transparent: true
} );
this._init();
}
/**
* Updates IK bones visualization.
*/
updateMatrixWorld( force ) {
const mesh = this.root;
if ( this.visible ) {
let offset = 0;
const iks = this.iks;
const bones = mesh.skeleton.bones;
_matrix.copy( mesh.matrixWorld ).invert();
for ( let i = 0, il = iks.length; i < il; i ++ ) {
const ik = iks[ i ];
const targetBone = bones[ ik.target ];
const effectorBone = bones[ ik.effector ];
const targetMesh = this.children[ offset ++ ];
const effectorMesh = this.children[ offset ++ ];
targetMesh.position.copy( getPosition( targetBone, _matrix ) );
effectorMesh.position.copy( getPosition( effectorBone, _matrix ) );
for ( let j = 0, jl = ik.links.length; j < jl; j ++ ) {
const link = ik.links[ j ];
const linkBone = bones[ link.index ];
const linkMesh = this.children[ offset ++ ];
linkMesh.position.copy( getPosition( linkBone, _matrix ) );
}
const line = this.children[ offset ++ ];
const array = line.geometry.attributes.position.array;
setPositionOfBoneToAttributeArray( array, 0, targetBone, _matrix );
setPositionOfBoneToAttributeArray( array, 1, effectorBone, _matrix );
for ( let j = 0, jl = ik.links.length; j < jl; j ++ ) {
const link = ik.links[ j ];
const linkBone = bones[ link.index ];
setPositionOfBoneToAttributeArray( array, j + 2, linkBone, _matrix );
}
line.geometry.attributes.position.needsUpdate = true;
}
}
this.matrix.copy( mesh.matrixWorld );
super.updateMatrixWorld( force );
} // private method
_init() {
const scope = this;
const iks = this.iks;
function createLineGeometry( ik ) {
const geometry = new THREE.BufferGeometry();
const vertices = new Float32Array( ( 2 + ik.links.length ) * 3 );
geometry.setAttribute( 'position', new THREE.BufferAttribute( vertices, 3 ) );
return geometry;
}
function createTargetMesh() {
return new THREE.Mesh( scope.sphereGeometry, scope.targetSphereMaterial );
}
function createEffectorMesh() {
return new THREE.Mesh( scope.sphereGeometry, scope.effectorSphereMaterial );
}
function createLinkMesh() {
return new THREE.Mesh( scope.sphereGeometry, scope.linkSphereMaterial );
}
function createLine( ik ) {
return new THREE.Line( createLineGeometry( ik ), scope.lineMaterial );
}
for ( let i = 0, il = iks.length; i < il; i ++ ) {
const ik = iks[ i ];
this.add( createTargetMesh() );
this.add( createEffectorMesh() );
for ( let j = 0, jl = ik.links.length; j < jl; j ++ ) {
this.add( createLinkMesh() );
}
this.add( createLine( ik ) );
}
}
}
THREE.CCDIKHelper = CCDIKHelper;
THREE.CCDIKSolver = CCDIKSolver;
} )();
