Accueil / npm / three@0.186.1 / examples / jsm / animation / CCDIKSolver.js
CCDIKSolver.js
import {
BufferAttribute,
BufferGeometry,
Color,
Line,
LineBasicMaterial,
Matrix4,
Mesh,
MeshBasicMaterial,
Object3D,
Quaternion,
SphereGeometry,
Vector3
} from 'three';
const _quaternion = new Quaternion();
const _targetPos = new Vector3();
const _targetVec = new Vector3();
const _effectorPos = new Vector3();
const _effectorVec = new Vector3();
const _linkPos = new Vector3();
const _invLinkQ = new Quaternion();
const _linkScale = new Vector3();
const _axis = new Vector3();
const _vector = new Vector3();
const _matrix = new Matrix4();
/**
* This class solves the Inverse Kinematics Problem with a [CCD Algorithm](https://web.archive.org/web/20221206080850/https://sites.google.com/site/auraliusproject/ccd-algorithm).
*
* `CCDIKSolver` is designed to work with instances of {@link SkinnedMesh}.
*
* @three_import import { CCDIKSolver } from 'three/addons/animation/CCDIKSolver.js';
*/
class CCDIKSolver {
/**
* @param {SkinnedMesh} mesh - The skinned mesh.
* @param {Array<CCDIKSolver~IK>} [iks=[]] - The IK objects.
*/
constructor( mesh, iks = [] ) {
/**
* The skinned mesh.
*
* @type {SkinnedMesh}
*/
this.mesh = mesh;
/**
* The IK objects.
*
* @type {Array<CCDIKSolver~IK>}
*/
this.iks = iks;
this._initialQuaternions = [];
this._workingQuaternion = new Quaternion();
for ( const ik of iks ) {
const chainQuats = [];
for ( let i = 0; i < ik.links.length; i ++ ) {
chainQuats.push( new Quaternion() );
}
this._initialQuaternions.push( chainQuats );
}
this._valid();
}
/**
* Updates all IK bones by solving the CCD algorithm.
*
* @param {number} [globalBlendFactor=1.0] - Blend factor applied if an IK chain doesn't have its own .blendFactor.
* @return {CCDIKSolver} A reference to this instance.
*/
update( globalBlendFactor = 1.0 ) {
const iks = this.iks;
for ( let i = 0, il = iks.length; i < il; i ++ ) {
this.updateOne( iks[ i ], globalBlendFactor );
}
return this;
}
/**
* Updates one IK bone solving the CCD algorithm.
*
* @param {CCDIKSolver~IK} ik - The IK to update.
* @param {number} [overrideBlend=1.0] - If the IK object does not define `blendFactor`, this value is used.
* @return {CCDIKSolver} A reference to this instance.
*/
updateOne( ik, overrideBlend = 1.0 ) {
const chainBlend = ik.blendFactor !== undefined ? ik.blendFactor : overrideBlend;
const bones = this.mesh.skeleton.bones;
const chainIndex = this.iks.indexOf( ik );
const initialQuaternions = this._initialQuaternions[ chainIndex ];
// 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;
if ( chainBlend < 1.0 ) {
for ( let j = 0; j < links.length; j ++ ) {
const linkIndex = links[ j ].index;
initialQuaternions[ j ].copy( bones[ linkIndex ].quaternion );
}
}
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
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();
_quaternion.setFromAxisAngle( _axis, angle );
link.quaternion.multiply( _quaternion );
// TODO: re-consider the limitation specification
if ( limitation !== undefined ) {
let c = link.quaternion.w;
if ( c > 1.0 ) c = 1.0;
// preserve sign of the rotation along the limitation axis,
// otherwise negative rotations get mirrored to positive
const dot = link.quaternion.x * limitation.x + link.quaternion.y * limitation.y + link.quaternion.z * limitation.z;
const sign = dot < 0 ? - 1 : 1;
const c2 = sign * 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;
}
if ( chainBlend < 1.0 ) {
for ( let j = 0; j < links.length; j ++ ) {
const linkIndex = links[ j ].index;
const link = bones[ linkIndex ];
this._workingQuaternion.copy( initialQuaternions[ j ] ).slerp( link.quaternion, chainBlend );
link.quaternion.copy( this._workingQuaternion );
link.updateMatrixWorld( true );
}
}
return this;
}
/**
* Creates a helper for visualizing the CCDIK.
*
* @param {number} sphereSize - The sphere size.
* @return {CCDIKHelper} The created helper.
*/
createHelper( sphereSize ) {
return new CCDIKHelper( this.mesh, this.iks, sphereSize );
}
// 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;
}
/**
* Helper for visualizing IK bones.
*
* @augments Object3D
* @three_import import { CCDIKHelper } from 'three/addons/animation/CCDIKSolver.js';
*/
class CCDIKHelper extends Object3D {
/**
* @param {SkinnedMesh} mesh - The skinned mesh.
* @param {Array<CCDIKSolver~IK>} [iks=[]] - The IK objects.
* @param {number} [sphereSize=0.25] - The sphere size.
*/
constructor( mesh, iks = [], sphereSize = 0.25 ) {
super();
/**
* The skinned mesh this helper refers to.
*
* @type {SkinnedMesh}
*/
this.root = mesh;
/**
* The IK objects.
*
* @type {Array<CCDIKSolver~IK>}
*/
this.iks = iks;
this.matrix.copy( mesh.matrixWorld );
this.matrixAutoUpdate = false;
/**
* The helpers sphere geometry.
*
* @type {SphereGeometry}
*/
this.sphereGeometry = new SphereGeometry( sphereSize, 16, 8 );
/**
* The material for the target spheres.
*
* @type {MeshBasicMaterial}
*/
this.targetSphereMaterial = new MeshBasicMaterial( {
color: new Color( 0xff8888 ),
depthTest: false,
depthWrite: false,
transparent: true
} );
/**
* The material for the effector spheres.
*
* @type {MeshBasicMaterial}
*/
this.effectorSphereMaterial = new MeshBasicMaterial( {
color: new Color( 0x88ff88 ),
depthTest: false,
depthWrite: false,
transparent: true
} );
/**
* The material for the link spheres.
*
* @type {MeshBasicMaterial}
*/
this.linkSphereMaterial = new MeshBasicMaterial( {
color: new Color( 0x8888ff ),
depthTest: false,
depthWrite: false,
transparent: true
} );
/**
* A global line material.
*
* @type {LineBasicMaterial}
*/
this.lineMaterial = new LineBasicMaterial( {
color: new Color( 0xff0000 ),
depthTest: false,
depthWrite: false,
transparent: true
} );
this._init();
}
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 );
}
/**
* Frees the GPU-related resources allocated by this instance.
* Call this method whenever this instance is no longer used in your app.
*/
dispose() {
this.sphereGeometry.dispose();
this.targetSphereMaterial.dispose();
this.effectorSphereMaterial.dispose();
this.linkSphereMaterial.dispose();
this.lineMaterial.dispose();
const children = this.children;
for ( let i = 0; i < children.length; i ++ ) {
const child = children[ i ];
if ( child.isLine ) child.geometry.dispose();
}
}
// private method
_init() {
const scope = this;
const iks = this.iks;
function createLineGeometry( ik ) {
const geometry = new BufferGeometry();
const vertices = new Float32Array( ( 2 + ik.links.length ) * 3 );
geometry.setAttribute( 'position', new BufferAttribute( vertices, 3 ) );
return geometry;
}
function createTargetMesh() {
return new Mesh( scope.sphereGeometry, scope.targetSphereMaterial );
}
function createEffectorMesh() {
return new Mesh( scope.sphereGeometry, scope.effectorSphereMaterial );
}
function createLinkMesh() {
return new Mesh( scope.sphereGeometry, scope.linkSphereMaterial );
}
function createLine( ik ) {
return new 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 ) );
}
}
}
/**
* This type represents IK configuration objects.
*
* @typedef {Object} CCDIKSolver~IK
* @property {number} target - The target bone index which refers to a bone in the `Skeleton.bones` array.
* @property {number} effector - The effector bone index which refers to a bone in the `Skeleton.bones` array.
* @property {Array<CCDIKSolver~BoneLink>} links - An array of bone links.
* @property {number} [iteration=1] - Iteration number of calculation. Smaller is faster but less precise.
* @property {number} [minAngle] - Minimum rotation angle in a step in radians.
* @property {number} [maxAngle] - Minimum rotation angle in a step in radians.
* @property {number} [blendFactor] - The blend factor.
**/
/**
* This type represents bone links.
*
* @typedef {Object} CCDIKSolver~BoneLink
* @property {number} index - The index of a linked bone which refers to a bone in the `Skeleton.bones` array.
* @property {number} [limitation] - Rotation axis.
* @property {number} [rotationMin] - Rotation minimum limit.
* @property {number} [rotationMax] - Rotation maximum limit.
* @property {boolean} [enabled=true] - Whether the link is enabled or not.
**/
export { CCDIKSolver, CCDIKHelper };