first commit

public/sdk/three/jsm/physics/RapierPhysics.js

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+import { Clock, Vector3, Quaternion, Matrix4 } from 'three';
+
+const RAPIER_PATH = 'https://cdn.skypack.dev/@dimforge/rapier3d-compat@0.12.0';
+
+const frameRate = 60;
+
+const _scale = new Vector3( 1, 1, 1 );
+const ZERO = new Vector3();
+
+let RAPIER = null;
+
+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;
+
+		return RAPIER.ColliderDesc.cuboid( sx, sy, sz );
+
+	} else if ( geometry.type === 'SphereGeometry' || geometry.type === 'IcosahedronGeometry' ) {
+
+		const radius = parameters.radius !== undefined ? parameters.radius : 1;
+		return RAPIER.ColliderDesc.ball( radius );
+
+	}
+
+	return null;
+
+}
+
+async function RapierPhysics() {
+
+	if ( RAPIER === null ) {
+
+		RAPIER = await import( RAPIER_PATH );
+		await RAPIER.init();
+
+	}
+
+	// Docs: https://rapier.rs/docs/api/javascript/JavaScript3D/
+
+	const gravity = new Vector3( 0.0, - 9.81, 0.0 );
+	const world = new RAPIER.World( gravity );
+
+	const meshes = [];
+	const meshMap = new WeakMap();
+
+	const _vector = new Vector3();
+	const _quaternion = new Quaternion();
+	const _matrix = new Matrix4();
+
+	function addScene( scene ) {
+
+		scene.traverse( function ( child ) {
+
+			if ( child.isMesh ) {
+
+				const physics = child.userData.physics;
+
+				if ( physics ) {
+
+					addMesh( child, physics.mass, physics.restitution );
+
+				}
+
+			}
+
+		} );
+
+	}
+
+	function addMesh( mesh, mass = 0, restitution = 0 ) {
+
+		const shape = getShape( mesh.geometry );
+
+		if ( shape === null ) return;
+
+		shape.setMass( mass );
+		shape.setRestitution( restitution );
+
+		const body = mesh.isInstancedMesh
+							? createInstancedBody( mesh, mass, shape )
+							: createBody( mesh.position, mesh.quaternion, mass, shape );
+
+		if ( mass > 0 ) {
+
+			meshes.push( mesh );
+			meshMap.set( mesh, body );
+
+		}
+
+	}
+
+	function createInstancedBody( mesh, mass, shape ) {
+
+		const array = mesh.instanceMatrix.array;
+
+		const bodies = [];
+
+		for ( let i = 0; i < mesh.count; i ++ ) {
+
+			const position = _vector.fromArray( array, i * 16 + 12 );
+			bodies.push( createBody( position, null, mass, shape ) );
+
+		}
+
+		return bodies;
+
+	}
+
+	function createBody( position, quaternion, mass, shape ) {
+
+		const desc = mass > 0 ? RAPIER.RigidBodyDesc.dynamic() : RAPIER.RigidBodyDesc.fixed();
+		desc.setTranslation( ...position );
+		if ( quaternion !== null ) desc.setRotation( quaternion );
+
+		const body = world.createRigidBody( desc );
+		world.createCollider( shape, body );
+
+		return body;
+
+	}
+
+	function setMeshPosition( mesh, position, index = 0 ) {
+
+		let body = meshMap.get( mesh );
+
+		if ( mesh.isInstancedMesh ) {
+
+			body = body[ index ];
+
+		}
+
+		body.setAngvel( ZERO );
+		body.setLinvel( ZERO );
+		body.setTranslation( position );
+
+	}
+
+	function setMeshVelocity( mesh, velocity, index = 0 ) {
+
+		let body = meshMap.get( mesh );
+
+		if ( mesh.isInstancedMesh ) {
+
+			body = body[ index ];
+
+		}
+
+		body.setLinvel( velocity );
+
+	}
+
+	//
+
+	const clock = new Clock();
+
+	function step() {
+
+		world.timestep = clock.getDelta();
+		world.step();
+
+		//
+
+		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 position = body.translation();
+					_quaternion.copy( body.rotation() );
+
+					_matrix.compose( position, _quaternion, _scale ).toArray( array, j * 16 );
+
+				}
+
+				mesh.instanceMatrix.needsUpdate = true;
+				mesh.computeBoundingSphere();
+
+			} else {
+
+				const body = meshMap.get( mesh );
+
+				mesh.position.copy( body.translation() );
+				mesh.quaternion.copy( body.rotation() );
+
+			}
+
+		}
+
+	}
+
+	// animate
+
+	setInterval( step, 1000 / frameRate );
+
+	return {
+		addScene: addScene,
+		addMesh: addMesh,
+		setMeshPosition: setMeshPosition,
+		setMeshVelocity: setMeshVelocity
+	};
+
+}
+
+export { RapierPhysics };