var input = document.getElementById( 'input' );
input.addEventListener( 'change', function( event ) {
    var file = this.files[ 0 ];
    var reader = new FileReader();
    reader.addEventListener( 'load', function ( event ) {
        var contents = event.target.result;
        var geometry = new STLLoader().parse( contents );
        var material = new THREE.MeshStandardMaterial();
        var mesh = new THREE.Mesh( geometry, material );
        mesh.castShadow = true;
        mesh.receiveShadow = true;
        scene.add( mesh );
    }, false );
    if ( reader.readAsBinaryString !== undefined ) {
        reader.readAsBinaryString( file );
    } else {
        reader.readAsArrayBuffer( file );
    }
} );