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MMDPhysics improvement (#9989)
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* MMDPhysics improvement

* Add property defined check
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@takahirox @mrdoob
takahirox authored and mrdoob committed Nov 2, 2016
1 parent 4a1db7b commit 544770e
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Showing 4 changed files with 289 additions and 38 deletions.
262 changes: 237 additions & 25 deletions examples/js/animation/MMDPhysics.js
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Original file line number Diff line number Diff line change
Expand Up @@ -4,49 +4,79 @@
* Dependencies
* - Ammo.js https://github.com/kripken/ammo.js
*
*
* MMD specific Physics class.
*
* See THREE.MMDLoader for the passed parameter list of RigidBody/Constraint.
*
* Requirement:
* - don't change object's scale from (1,1,1) after setting physics to object
*
* TODO
* - optimize for the performance
* - use Physijs http://chandlerprall.github.io/Physijs/
* and improve the performance by making use of Web worker.
* - if possible, make this class being non-MMD specific.
* - object scale change support
*/

THREE.MMDPhysics = function ( mesh, params ) {

if ( params === undefined ) params = {};

this.mesh = mesh;
this.helper = new THREE.MMDPhysics.PhysicsHelper();
this.helper = new THREE.MMDPhysics.ResourceHelper();

/*
* Note: Default 1 / 65 unit step is a workaround that
* some bones go wrong at near 60fps if it's 1 / 60.
* Be careful that small unitStep could cause heavy
* physics calculation.
*/
this.unitStep = ( params && params.unitStep ) ? params.unitStep : 1 / 65;
this.maxStepNum = ( params && params.maxStepNum ) ? params.maxStepNum : 3;
this.unitStep = ( params.unitStep !== undefined ) ? params.unitStep : 1 / 60;
this.maxStepNum = ( params.maxStepNum !== undefined ) ? params.maxStepNum : 3;

this.world = null;
this.bodies = [];
this.constraints = [];

this.init();
this.init( mesh );

};

THREE.MMDPhysics.prototype = {

constructor: THREE.MMDPhysics,

init: function () {
init: function ( mesh ) {

var parent = mesh.parent;

if ( parent !== null ) {

parent.remove( mesh );

}

var currentPosition = mesh.position.clone();
var currentRotation = mesh.rotation.clone();
var currentScale = mesh.scale.clone();

mesh.position.set( 0, 0, 0 );
mesh.rotation.set( 0, 0, 0 );
mesh.scale.set( 1, 1, 1 );

mesh.updateMatrixWorld( true );

this.initWorld();
this.initRigidBodies();
this.initConstraints();

if ( parent !== null ) {

parent.add( mesh );

}

mesh.position.copy( currentPosition );
mesh.rotation.copy( currentRotation );
mesh.scale.copy( currentScale );

mesh.updateMatrixWorld( true );

this.reset();

},
Expand All @@ -58,7 +88,7 @@ THREE.MMDPhysics.prototype = {
var cache = new Ammo.btDbvtBroadphase();
var solver = new Ammo.btSequentialImpulseConstraintSolver();
var world = new Ammo.btDiscreteDynamicsWorld( dispatcher, cache, solver, config );
world.setGravity( new Ammo.btVector3( 0, -10 * 10, 0 ) );
world.setGravity( new Ammo.btVector3( 0, -9.8 * 10, 0 ) );
this.world = world;

},
Expand Down Expand Up @@ -99,6 +129,13 @@ THREE.MMDPhysics.prototype = {
var stepTime = delta;
var maxStepNum = ( ( delta / unitStep ) | 0 ) + 1;

if ( stepTime < unitStep ) {

stepTime = unitStep;
maxStepNum = 1;

}

if ( maxStepNum > this.maxStepNum ) {

maxStepNum = this.maxStepNum;
Expand Down Expand Up @@ -145,7 +182,7 @@ THREE.MMDPhysics.prototype = {

for ( var i = 0; i < cycles; i++ ) {

this.update( 1 );
this.update( 1 / 60 );

}

Expand All @@ -162,12 +199,13 @@ THREE.MMDPhysics.prototype = {
*
* 2. provide simple Ammo object operations.
*/
THREE.MMDPhysics.PhysicsHelper = function () {
THREE.MMDPhysics.ResourceHelper = function () {

// for Three.js
this.threeVector3s = [];
this.threeMatrix4s = [];
this.threeQuaternions = [];
this.threeEulers = [];

// for Ammo.js
this.transforms = [];
Expand All @@ -176,7 +214,7 @@ THREE.MMDPhysics.PhysicsHelper = function () {

};

THREE.MMDPhysics.PhysicsHelper.prototype = {
THREE.MMDPhysics.ResourceHelper.prototype = {

allocThreeVector3: function () {

Expand Down Expand Up @@ -214,6 +252,18 @@ THREE.MMDPhysics.PhysicsHelper.prototype = {

},

allocThreeEuler: function () {

return ( this.threeEulers.length > 0 ) ? this.threeEulers.pop() : new THREE.Euler();

},

freeThreeEuler: function ( e ) {

this.threeEulers.push( e );

},

allocTransform: function () {

return ( this.transforms.length > 0 ) ? this.transforms.pop() : new Ammo.btTransform();
Expand Down Expand Up @@ -314,7 +364,13 @@ THREE.MMDPhysics.PhysicsHelper.prototype = {

setBasisFromArray3: function ( t, a ) {

t.getBasis().setEulerZYX( a[ 0 ], a[ 1 ], a[ 2 ] );
var thQ = this.allocThreeQuaternion();
var thE = this.allocThreeEuler();
thE.set( a[ 0 ], a[ 1 ], a[ 2 ] );
this.setBasisFromArray4( t, thQ.setFromEuler( thE ).toArray() );

this.freeThreeEuler( thE );
this.freeThreeQuaternion( thQ );

},

Expand Down Expand Up @@ -598,7 +654,7 @@ THREE.MMDPhysics.RigidBody.prototype = {

init: function () {

function generateShape ( p ) {
function generateShape( p ) {

switch( p.shapeType ) {

Expand Down Expand Up @@ -648,13 +704,19 @@ THREE.MMDPhysics.RigidBody.prototype = {

var info = new Ammo.btRigidBodyConstructionInfo( weight, state, shape, localInertia );
info.set_m_friction( params.friction );
info.set_m_restitution( params.restriction );
info.set_m_restitution( params.restitution );

var body = new Ammo.btRigidBody( info );

if ( params.type === 0 ) {

body.setCollisionFlags( body.getCollisionFlags() | 2 );

/*
* It'd be better to comment out this line though in general I should call this method
* because I'm not sure why but physics will be more like MMD's
* if I comment out.
*/
body.setActivationState( 4 );

}
Expand Down Expand Up @@ -695,12 +757,6 @@ THREE.MMDPhysics.RigidBody.prototype = {

}

if ( this.params.type === 2 ) {

this.setPositionFromBone();

}

},

updateBone: function () {
Expand All @@ -721,6 +777,12 @@ THREE.MMDPhysics.RigidBody.prototype = {

this.bone.updateMatrixWorld( true );

if ( this.params.type === 2 ) {

this.setPositionFromBone();

}

},

getBoneTransform: function () {
Expand Down Expand Up @@ -932,6 +994,23 @@ THREE.MMDPhysics.Constraint.prototype = {

}

/*
* Currently(10/31/2016) official ammo.js doesn't support
* btGeneric6DofSpringConstraint.setParam method.
* You need custom ammo.js (add the method into idl) if you wanna use.
* By setting this parameter, physics will be more like MMD's
*/
if ( constraint.setParam !== undefined ) {

for ( var i = 0; i < 6; i ++ ) {

// this parameter is from http://www20.atpages.jp/katwat/three.js_r58/examples/mytest37/mmd.three.js
constraint.setParam( 2, 0.475, i );

}

}

this.world.addConstraint( constraint, true );
this.constraint = constraint;

Expand All @@ -950,3 +1029,136 @@ THREE.MMDPhysics.Constraint.prototype = {
}

};


/*
* This helper displays rigid bodies of mesh for debug.
* It should be under Scene because it just sets world position/roration to meshes
* for simplicity.
*/
THREE.MMDPhysicsHelper = function ( mesh ) {

if ( mesh.physics === undefined || mesh.geometry.rigidBodies === undefined ) {

throw 'THREE.MMDPhysicsHelper requires physics in mesh and rigidBodies in mesh.geometry.';

}

THREE.Object3D.call( this );

this.mesh = mesh;

this._init();

};

THREE.MMDPhysicsHelper.prototype = Object.create( THREE.Object3D.prototype );
THREE.MMDPhysicsHelper.prototype.constructor = THREE.MMDPhysicsHelper;

THREE.MMDPhysicsHelper.prototype._init = function () {

function createGeometry( param ) {

switch ( param.shapeType ) {

case 0:
return new THREE.SphereBufferGeometry( param.width, 16, 8 );

case 1:
return new THREE.BoxBufferGeometry( param.width * 2, param.height * 2, param.depth * 2, 8, 8, 8);

case 2:
return new createCapsuleGeometry( param.width, param.height, 16, 8 );

default:
return null;

}

}

// copy from http://www20.atpages.jp/katwat/three.js_r58/examples/mytest37/mytest37.js?ver=20160815
function createCapsuleGeometry( radius, cylinderHeight, segmentsRadius, segmentsHeight ) {

var geometry = new THREE.CylinderBufferGeometry( radius, radius, cylinderHeight, segmentsRadius, segmentsHeight, true );
var upperSphere = new THREE.Mesh( new THREE.SphereBufferGeometry( radius, segmentsRadius, segmentsHeight, 0, Math.PI * 2, 0, Math.PI / 2 ) );
var lowerSphere = new THREE.Mesh( new THREE.SphereBufferGeometry( radius, segmentsRadius, segmentsHeight, 0, Math.PI * 2, Math.PI / 2, Math.PI / 2 ) );

upperSphere.position.set( 0, cylinderHeight / 2, 0 );
lowerSphere.position.set( 0, -cylinderHeight / 2, 0 );

upperSphere.updateMatrix();
lowerSphere.updateMatrix();

geometry.merge( upperSphere.geometry, upperSphere.matrix );
geometry.merge( lowerSphere.geometry, lowerSphere.matrix );

return geometry;

}


function createMaterial( param ) {

var color;

switch ( param.type ) {

case 0:
color = 0xff8888;
break;

case 1:
color = 0x88ff88;
break;

case 2:
color = 0x8888ff;
break;

default:
color = 0x000000;
break;

}

return new THREE.MeshBasicMaterial( {
color: new THREE.Color( color ),
wireframe: true,
depthTest: false,
depthWrite: false,
opacity: 0.25,
transparent: true
} );

}

for ( var i = 0, il = this.mesh.geometry.rigidBodies.length; i < il; i ++ ) {

var param = this.mesh.geometry.rigidBodies[ i ];

var mesh = new THREE.Mesh( createGeometry( param ), createMaterial( param ) );
this.add( mesh );

}

};

THREE.MMDPhysicsHelper.prototype.update = function () {

for ( var i = 0, il = this.mesh.geometry.rigidBodies.length; i < il; i ++ ) {

var body = this.mesh.physics.bodies[ i ].body;
var mesh = this.children[ i ];

var tr = body.getCenterOfMassTransform();

var o = tr.getOrigin();
var r = tr.getRotation();

mesh.position.set( o.x(), o.y(), o.z() );
mesh.quaternion.set( r.x(), r.y(), r.z(), r.w() );

}

};
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