( function () {
async function AmmoPhysics() {
if ( 'Ammo' in window === false ) {
console.error( 'AmmoPhysics: Couldn\'t find Ammo.js' );
return;
}
const AmmoLib = await Ammo(); // eslint-disable-line no-undef
const frameRate = 60;
const collisionConfiguration = new AmmoLib.btDefaultCollisionConfiguration();
const dispatcher = new AmmoLib.btCollisionDispatcher( collisionConfiguration );
const broadphase = new AmmoLib.btDbvtBroadphase();
const solver = new AmmoLib.btSequentialImpulseConstraintSolver();
const world = new AmmoLib.btDiscreteDynamicsWorld( dispatcher, broadphase, solver, collisionConfiguration );
world.setGravity( new AmmoLib.btVector3( 0, - 9.8, 0 ) );
const worldTransform = new AmmoLib.btTransform(); //
function getShape( geometry ) {
const parameters = geometry.parameters; // TODO change type to is*
if ( geometry.type === 'BoxGeometry' ) {
const sx = parameters.width !== undefined ? parameters.width / 2 : 0.5;
const sy = parameters.height !== undefined ? parameters.height / 2 : 0.5;
const sz = parameters.depth !== undefined ? parameters.depth / 2 : 0.5;
const shape = new AmmoLib.btBoxShape( new AmmoLib.btVector3( sx, sy, sz ) );
shape.setMargin( 0.05 );
return shape;
} else if ( geometry.type === 'SphereGeometry' || geometry.type === 'IcosahedronGeometry' ) {
const radius = parameters.radius !== undefined ? parameters.radius : 1;
const shape = new AmmoLib.btSphereShape( radius );
shape.setMargin( 0.05 );
return shape;
}
return null;
}
const meshes = [];
const meshMap = new WeakMap();
function addMesh( mesh, mass = 0 ) {
const shape = getShape( mesh.geometry );
if ( shape !== null ) {
if ( mesh.isInstancedMesh ) {
handleInstancedMesh( mesh, mass, shape );
} else if ( mesh.isMesh ) {
handleMesh( mesh, mass, shape );
}
}
}
function handleMesh( mesh, mass, shape ) {
const position = mesh.position;
const quaternion = mesh.quaternion;
const transform = new AmmoLib.btTransform();
transform.setIdentity();
transform.setOrigin( new AmmoLib.btVector3( position.x, position.y, position.z ) );
transform.setRotation( new AmmoLib.btQuaternion( quaternion.x, quaternion.y, quaternion.z, quaternion.w ) );
const motionState = new AmmoLib.btDefaultMotionState( transform );
const localInertia = new AmmoLib.btVector3( 0, 0, 0 );
shape.calculateLocalInertia( mass, localInertia );
const rbInfo = new AmmoLib.btRigidBodyConstructionInfo( mass, motionState, shape, localInertia );
const body = new AmmoLib.btRigidBody( rbInfo ); // body.setFriction( 4 );
world.addRigidBody( body );
if ( mass > 0 ) {
meshes.push( mesh );
meshMap.set( mesh, body );
}
}
function handleInstancedMesh( mesh, mass, shape ) {
const array = mesh.instanceMatrix.array;
const bodies = [];
for ( let i = 0; i < mesh.count; i ++ ) {
const index = i * 16;
const transform = new AmmoLib.btTransform();
transform.setFromOpenGLMatrix( array.slice( index, index + 16 ) );
const motionState = new AmmoLib.btDefaultMotionState( transform );
const localInertia = new AmmoLib.btVector3( 0, 0, 0 );
shape.calculateLocalInertia( mass, localInertia );
const rbInfo = new AmmoLib.btRigidBodyConstructionInfo( mass, motionState, shape, localInertia );
const body = new AmmoLib.btRigidBody( rbInfo );
world.addRigidBody( body );
bodies.push( body );
}
if ( mass > 0 ) {
meshes.push( mesh );
meshMap.set( mesh, bodies );
}
} //
function setMeshPosition( mesh, position, index = 0 ) {
if ( mesh.isInstancedMesh ) {
const bodies = meshMap.get( mesh );
const body = bodies[ index ];
body.setAngularVelocity( new AmmoLib.btVector3( 0, 0, 0 ) );
body.setLinearVelocity( new AmmoLib.btVector3( 0, 0, 0 ) );
worldTransform.setIdentity();
worldTransform.setOrigin( new AmmoLib.btVector3( position.x, position.y, position.z ) );
body.setWorldTransform( worldTransform );
} else if ( mesh.isMesh ) {
const body = meshMap.get( mesh );
body.setAngularVelocity( new AmmoLib.btVector3( 0, 0, 0 ) );
body.setLinearVelocity( new AmmoLib.btVector3( 0, 0, 0 ) );
worldTransform.setIdentity();
worldTransform.setOrigin( new AmmoLib.btVector3( position.x, position.y, position.z ) );
body.setWorldTransform( worldTransform );
}
} //
let lastTime = 0;
function step() {
const time = performance.now();
if ( lastTime > 0 ) {
const delta = ( time - lastTime ) / 1000; // console.time( 'world.step' );
world.stepSimulation( delta, 10 ); // console.timeEnd( 'world.step' );
}
lastTime = time; //
for ( let i = 0, l = meshes.length; i < l; i ++ ) {
const mesh = meshes[ i ];
if ( mesh.isInstancedMesh ) {
const array = mesh.instanceMatrix.array;
const bodies = meshMap.get( mesh );
for ( let j = 0; j < bodies.length; j ++ ) {
const body = bodies[ j ];
const motionState = body.getMotionState();
motionState.getWorldTransform( worldTransform );
const position = worldTransform.getOrigin();
const quaternion = worldTransform.getRotation();
compose( position, quaternion, array, j * 16 );
}
mesh.instanceMatrix.needsUpdate = true;
} else if ( mesh.isMesh ) {
const body = meshMap.get( mesh );
const motionState = body.getMotionState();
motionState.getWorldTransform( worldTransform );
const position = worldTransform.getOrigin();
const quaternion = worldTransform.getRotation();
mesh.position.set( position.x(), position.y(), position.z() );
mesh.quaternion.set( quaternion.x(), quaternion.y(), quaternion.z(), quaternion.w() );
}
}
} // animate
setInterval( step, 1000 / frameRate );
return {
addMesh: addMesh,
setMeshPosition: setMeshPosition // addCompoundMesh
};
}
function compose( position, quaternion, array, index ) {
const x = quaternion.x(),
y = quaternion.y(),
z = quaternion.z(),
w = quaternion.w();
const x2 = x + x,
y2 = y + y,
z2 = z + z;
const xx = x * x2,
xy = x * y2,
xz = x * z2;
const yy = y * y2,
yz = y * z2,
zz = z * z2;
const wx = w * x2,
wy = w * y2,
wz = w * z2;
array[ index + 0 ] = 1 - ( yy + zz );
array[ index + 1 ] = xy + wz;
array[ index + 2 ] = xz - wy;
array[ index + 3 ] = 0;
array[ index + 4 ] = xy - wz;
array[ index + 5 ] = 1 - ( xx + zz );
array[ index + 6 ] = yz + wx;
array[ index + 7 ] = 0;
array[ index + 8 ] = xz + wy;
array[ index + 9 ] = yz - wx;
array[ index + 10 ] = 1 - ( xx + yy );
array[ index + 11 ] = 0;
array[ index + 12 ] = position.x();
array[ index + 13 ] = position.y();
array[ index + 14 ] = position.z();
array[ index + 15 ] = 1;
}
THREE.AmmoPhysics = AmmoPhysics;
} )();
