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<html lang="en">
<head>
<title>Amjs softbody rope demo</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
<style>
body {
color: #61443e;
font-family:Monospace;
font-size:13px;
text-align:center;
background-color: #bfd1e5;
margin: 0px;
overflow: hidden;
}
#info {
position: absolute;
top: 0px; width: 100%;
padding: 5px;
}
a {
color: #a06851;
}
</style>
</head>
<body>
<div id="info">Ammo.js physics soft body rope demo<br>Press Q or A to move the arm.</div>
<div id="container"><br /><br /><br /><br /><br />Loading...</div>
<script src="js/libs/three.min.js"></script>
<script src="build/C3R.standalone.js"></script>
<script src="js/renderers/CSS3DRenderer.js"></script>
<script src="js/libs/ammo.js"></script>
<script src="js/controls/OrbitControls.js"></script>
<script src="js/libs/stats.min.js"></script>
<script>
// - Global variables -
// Graphics variables
var container, stats;
var camera, controls, scene, renderer;
var textureLoader;
var clock = new THREE.Clock();
// Physics variables
var gravityConstant = -9.8;
var collisionConfiguration;
var dispatcher;
var broadphase;
var solver;
var softBodySolver;
var physicsWorld;
var rigidBodies = [];
var margin = 0.05;
var hinge;
var rope;
var transformAux1 = new Ammo.btTransform();
var time = 0;
var armMovement = 0;
// - Main code -
init();
animate();
// - Functions -
function init() {
initGraphics();
initPhysics();
createObjects();
initInput();
}
function initGraphics() {
container = document.getElementById( 'container' );
camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.2, 2000 );
scene = new THREE.Scene();
scene.background = new THREE.Color( 0xbfd1e5 );
camera.position.set( -7, 5, 8 );
controls = new THREE.OrbitControls( camera );
controls.target.set( 0, 2, 0 );
controls.update();
//renderer = new THREE.WebGLRenderer();
renderer = new THREE.CSS3DRenderer();
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( window.innerWidth, window.innerHeight );
renderer.shadowMap.enabled = true;
textureLoader = new THREE.TextureLoader();
var ambientLight = new THREE.AmbientLight( 0x404040 );
scene.add( ambientLight );
var light = new THREE.DirectionalLight( 0xffffff, 1 );
light.position.set( -10, 10, 5 );
light.castShadow = true;
var d = 10;
light.shadow.camera.left = -d;
light.shadow.camera.right = d;
light.shadow.camera.top = d;
light.shadow.camera.bottom = -d;
light.shadow.camera.near = 2;
light.shadow.camera.far = 50;
light.shadow.mapSize.x = 1024;
light.shadow.mapSize.y = 1024;
scene.add( light );
container.innerHTML = "";
container.appendChild( renderer.domElement );
stats = new Stats();
stats.domElement.style.position = 'absolute';
stats.domElement.style.top = '0px';
container.appendChild( stats.domElement );
//
window.addEventListener( 'resize', onWindowResize, false );
}
function initPhysics() {
// Physics configuration
collisionConfiguration = new Ammo.btSoftBodyRigidBodyCollisionConfiguration();
dispatcher = new Ammo.btCollisionDispatcher( collisionConfiguration );
broadphase = new Ammo.btDbvtBroadphase();
solver = new Ammo.btSequentialImpulseConstraintSolver();
softBodySolver = new Ammo.btDefaultSoftBodySolver();
physicsWorld = new Ammo.btSoftRigidDynamicsWorld( dispatcher, broadphase, solver, collisionConfiguration, softBodySolver);
physicsWorld.setGravity( new Ammo.btVector3( 0, gravityConstant, 0 ) );
physicsWorld.getWorldInfo().set_m_gravity( new Ammo.btVector3( 0, gravityConstant, 0 ) );
}
function createObjects() {
var pos = new THREE.Vector3();
var quat = new THREE.Quaternion();
// Ground
pos.set( 0, - 0.5, 0 );
quat.set( 0, 0, 0, 1 );
var ground = createParalellepiped( 40, 1, 40, 0, pos, quat, new THREE.MeshPhongMaterial( { color: 0xFFFFFF } ), 16 );
ground.castShadow = true;
ground.receiveShadow = true;
textureLoader.load( "textures/grid.png", function( texture ) {
texture.wrapS = THREE.RepeatWrapping;
texture.wrapT = THREE.RepeatWrapping;
texture.repeat.set( 40, 40 );
ground.material.map = texture;
ground.material.needsUpdate = true;
} );
// Ball
var ballMass = 1.2;
var ballRadius = 0.6;
var ball = new THREE.Mesh( new THREE.SphereBufferGeometry( ballRadius, 8, 6 ), new THREE.MeshPhongMaterial( { color: 0x202020 } ) );
ball.castShadow = true;
ball.receiveShadow = true;
var ballShape = new Ammo.btSphereShape( ballRadius );
ballShape.setMargin( margin );
pos.set( -3, 2, 0 );
quat.set( 0, 0, 0, 1 );
createRigidBody( ball, ballShape, ballMass, pos, quat );
ball.userData.physicsBody.setFriction( 0.5 );
// Wall
var brickMass = 0.5;
var brickLength = 1.2;
var brickDepth = 0.6;
var brickHeight = brickLength * 0.5;
var numBricksLength = 6;
var numBricksHeight = 8;
var z0 = - numBricksLength * brickLength * 0.5;
pos.set( 0, brickHeight * 0.5, z0 );
quat.set( 0, 0, 0, 1 );
for ( var j = 0; j < numBricksHeight; j ++ ) {
var oddRow = ( j % 2 ) == 1;
pos.z = z0;
if ( oddRow ) {
pos.z -= 0.25 * brickLength;
}
var nRow = oddRow? numBricksLength + 1 : numBricksLength;
for ( var i = 0; i < nRow; i ++ ) {
var brickLengthCurrent = brickLength;
var brickMassCurrent = brickMass;
if ( oddRow && ( i == 0 || i == nRow - 1 ) ) {
brickLengthCurrent *= 0.5;
brickMassCurrent *= 0.5;
}
var brick = createParalellepiped( brickDepth, brickHeight, brickLengthCurrent, brickMassCurrent, pos, quat, createMaterial() );
brick.castShadow = true;
brick.receiveShadow = true;
if ( oddRow && ( i == 0 || i == nRow - 2 ) ) {
pos.z += 0.75 * brickLength;
}
else {
pos.z += brickLength;
}
}
pos.y += brickHeight;
}
// The rope
// Rope graphic object
var ropeNumSegments = 10;
var ropeLength = 4;
var ropeMass = 3;
var ropePos = ball.position.clone();
ropePos.y += ballRadius;
var segmentLength = ropeLength / ropeNumSegments;
var ropeGeometry = new THREE.BufferGeometry();
var ropeMaterial = new THREE.LineBasicMaterial( { color: 0x000000 } );
var ropePositions = [];
var ropeIndices = [];
for ( var i = 0; i < ropeNumSegments + 1; i++ ) {
ropePositions.push( ropePos.x, ropePos.y + i * segmentLength, ropePos.z );
}
for ( var i = 0; i < ropeNumSegments; i++ ) {
ropeIndices.push( i, i + 1 );
}
ropeGeometry.setIndex( new THREE.BufferAttribute( new Uint16Array( ropeIndices ), 1 ) );
ropeGeometry.addAttribute( 'position', new THREE.BufferAttribute( new Float32Array( ropePositions ), 3 ) );
ropeGeometry.computeBoundingSphere();
rope = new THREE.LineSegments( ropeGeometry, ropeMaterial );
rope.castShadow = true;
rope.receiveShadow = true;
scene.add( rope );
// Rope physic object
var softBodyHelpers = new Ammo.btSoftBodyHelpers();
var ropeStart = new Ammo.btVector3( ropePos.x, ropePos.y, ropePos.z );
var ropeEnd = new Ammo.btVector3( ropePos.x, ropePos.y + ropeLength, ropePos.z );
var ropeSoftBody = softBodyHelpers.CreateRope( physicsWorld.getWorldInfo(), ropeStart, ropeEnd, ropeNumSegments - 1, 0 );
var sbConfig = ropeSoftBody.get_m_cfg();
sbConfig.set_viterations( 10 );
sbConfig.set_piterations( 10 );
ropeSoftBody.setTotalMass( ropeMass, false );
Ammo.castObject( ropeSoftBody, Ammo.btCollisionObject ).getCollisionShape().setMargin( margin * 3 );
physicsWorld.addSoftBody( ropeSoftBody, 1, -1 );
rope.userData.physicsBody = ropeSoftBody;
// Disable deactivation
ropeSoftBody.setActivationState( 4 );
// The base
var armMass = 2;
var armLength = 3;
var pylonHeight = ropePos.y + ropeLength;
var baseMaterial = new THREE.MeshPhongMaterial( { color: 0x606060 } );
pos.set( ropePos.x, 0.1, ropePos.z - armLength );
quat.set( 0, 0, 0, 1 );
var base = createParalellepiped( 1, 0.2, 1, 0, pos, quat, baseMaterial );
base.castShadow = true;
base.receiveShadow = true;
pos.set( ropePos.x, 0.5 * pylonHeight, ropePos.z - armLength );
var pylon = createParalellepiped( 0.4, pylonHeight, 0.4, 0, pos, quat, baseMaterial );
pylon.castShadow = true;
pylon.receiveShadow = true;
pos.set( ropePos.x, pylonHeight + 0.2, ropePos.z - 0.5 * armLength );
var arm = createParalellepiped( 0.4, 0.4, armLength + 0.4, armMass, pos, quat, baseMaterial );
arm.castShadow = true;
arm.receiveShadow = true;
// Glue the rope extremes to the ball and the arm
var influence = 1;
ropeSoftBody.appendAnchor( 0, ball.userData.physicsBody, true, influence );
ropeSoftBody.appendAnchor( ropeNumSegments, arm.userData.physicsBody, true, influence );
// Hinge constraint to move the arm
var pivotA = new Ammo.btVector3( 0, pylonHeight * 0.5, 0 );
var pivotB = new Ammo.btVector3( 0, -0.2, - armLength * 0.5 );
var axis = new Ammo.btVector3( 0, 1, 0 );
hinge = new Ammo.btHingeConstraint( pylon.userData.physicsBody, arm.userData.physicsBody, pivotA, pivotB, axis, axis, true );
physicsWorld.addConstraint( hinge, true );
}
function createParalellepiped( sx, sy, sz, mass, pos, quat, material, scale ) {
scale = scale || 1;
var threeObject = new THREE.Mesh( new THREE.BoxBufferGeometry( sx*scale, sy*scale, sz*scale, 1, 1, 1 ), material );
var shape = new Ammo.btBoxShape( new Ammo.btVector3( sx * 0.5, sy * 0.5, sz * 0.5 ) );
shape.setMargin( margin );
createRigidBody( threeObject, shape, mass, pos, quat );
threeObject.scale.set(1/scale,1/scale,1/scale);
return threeObject;
}
function createRigidBody( threeObject, physicsShape, mass, pos, quat ) {
threeObject.position.copy( pos );
threeObject.quaternion.copy( quat );
var transform = new Ammo.btTransform();
transform.setIdentity();
transform.setOrigin( new Ammo.btVector3( pos.x, pos.y, pos.z ) );
transform.setRotation( new Ammo.btQuaternion( quat.x, quat.y, quat.z, quat.w ) );
var motionState = new Ammo.btDefaultMotionState( transform );
var localInertia = new Ammo.btVector3( 0, 0, 0 );
physicsShape.calculateLocalInertia( mass, localInertia );
var rbInfo = new Ammo.btRigidBodyConstructionInfo( mass, motionState, physicsShape, localInertia );
var body = new Ammo.btRigidBody( rbInfo );
threeObject.userData.physicsBody = body;
scene.add( threeObject );
if ( mass > 0 ) {
rigidBodies.push( threeObject );
// Disable deactivation
body.setActivationState( 4 );
}
physicsWorld.addRigidBody( body );
}
function createRandomColor() {
return Math.floor( Math.random() * ( 1 << 24 ) );
}
function createMaterial() {
return new THREE.MeshPhongMaterial( { color: createRandomColor() } );
}
function initInput() {
window.addEventListener( 'keydown', function( event ) {
switch ( event.keyCode ) {
// Q
case 81:
armMovement = 1;
break;
// A
case 65:
armMovement = - 1;
break;
}
}, false );
window.addEventListener( 'keyup', function( event ) {
armMovement = 0;
}, false );
}
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize( window.innerWidth, window.innerHeight );
}
function animate() {
requestAnimationFrame( animate );
render();
stats.update();
}
function render() {
var deltaTime = clock.getDelta();
updatePhysics( deltaTime );
renderer.render( scene, camera );
time += deltaTime;
}
function updatePhysics( deltaTime ) {
// Hinge control
hinge.enableAngularMotor( true, 1.5 * armMovement, 50 );
// Step world
physicsWorld.stepSimulation( deltaTime, 10 );
// Update rope
var softBody = rope.userData.physicsBody;
var ropePositions = rope.geometry.attributes.position.array;
var numVerts = ropePositions.length / 3;
var nodes = softBody.get_m_nodes();
var indexFloat = 0;
for ( var i = 0; i < numVerts; i ++ ) {
var node = nodes.at( i );
var nodePos = node.get_m_x();
ropePositions[ indexFloat++ ] = nodePos.x();
ropePositions[ indexFloat++ ] = nodePos.y();
ropePositions[ indexFloat++ ] = nodePos.z();
}
rope.geometry.attributes.position.needsUpdate = true;
// Update rigid bodies
for ( var i = 0, il = rigidBodies.length; i < il; i++ ) {
var objThree = rigidBodies[ i ];
var objPhys = objThree.userData.physicsBody;
var ms = objPhys.getMotionState();
if ( ms ) {
ms.getWorldTransform( transformAux1 );
var p = transformAux1.getOrigin();
var q = transformAux1.getRotation();
objThree.position.set( p.x(), p.y(), p.z() );
objThree.quaternion.set( q.x(), q.y(), q.z(), q.w() );
}
}
}
</script>
</body>
</html>