three.js half cylinder with hole

by yandeu

HTML

<script src="//cdn.rawgit.com/mrdoob/three.js/master/build/three.min.js"></script>

CSS

body {
	  margin: 0;
}

JavaScript

var camera, scene, renderer;
var geometry, material, mesh;

init();
animate();

function init() {

    camera = new THREE.PerspectiveCamera( 70, window.innerWidth / window.innerHeight, 0.01, 50 );
    camera.position.z = 15;

    scene = new THREE.Scene();
    
    var shape = new THREE.Shape()
    shape.arc(0, 0, 4, 0, Math.PI, false)
    shape.arc(4, 0, 3, Math.PI, 2 * Math.PI, true)

    var extrudeSettings = {
      curveSegments:10,
      depth: 1,
      bevelEnabled: false,
    }

    geometry = new THREE.ExtrudeGeometry(shape, extrudeSettings)
    material = new THREE.MeshNormalMaterial();

    mesh = new THREE.Mesh( geometry, material );
    scene.add( mesh );

    renderer = new THREE.WebGLRenderer( { antialias: true } );
    renderer.setSize( window.innerWidth, window.innerHeight );
    document.body.appendChild( renderer.domElement );

}

function animate() {

    requestAnimationFrame( animate );

    mesh.rotation.x += 0.01;
    mesh.rotation.y += 0.02;

    renderer.render( scene, camera );

}