How to convert .Obj file to Mesh?

I added geometry in THREE.Mesh. Working fine.

            var geometry = new THREE.SphereGeometry( 0.5, 40, 40 );
			var material = new THREE.MeshBasicMaterial( {color: 0x00ff00} );
			var player = new THREE.Mesh( geometry, material );
			scene.add( player );
			
			player.position.set(-3.5, 0.5, 5.5);

Now I want to add .obj file in Mesh (var player).

var loader = new THREE.OBJLoader();

			// load a resource
			loader.load(
		
				'meshes/car.obj',				
				function ( car ) {
					car.scale.set(0.2,0.2,0.2);
					car.position.set(-4.5, 5.3, 5.6);
					scene.add( car );

				},
				
			);

All Code

PatrolJS Demo
<style>
	body {
		font-family: Arial;
		background-color: #000;
		color: #fff;
		margin: 0px;
		overflow: hidden;
	}

	.info {
		padding: 10px;
		width: 100%;
		position: absolute;
		background-color: rgba(255, 0, 0, 0.5);
		font-size: 14px;
	}

	.info h1 {
		padding: 0;
		margin: 0;
	}

</style>

<body>

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.2/underscore-min.js"></script>
	<script>

		var container;

		var camera, scene, renderer, controls;

		var raycaster, intersectedObject;

		var mouse = new THREE.Vector2();

		var startTime	= Date.now();

		var windowHalfX = window.innerWidth / 2;
		var windowHalfY = window.innerHeight / 2;

		var lastFrameTime = 0;
		var maxFrameTime = 0.03;
		var elapsedTime = 0;

		var level;

		init();
		animate();

		var player, target;

		var playerNavMeshGroup;

		var calculatedPath = null;

		var pathLines;

		function init() {

			container = document.createElement( 'div' );
			document.body.appendChild( container );

			camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 2000 );
			camera.position.x = -10;
			camera.position.y = 14;
			camera.position.z = 10;

			scene = new THREE.Scene();

			var ambient = new THREE.AmbientLight( 0x101030 );
			scene.add( ambient );

			var directionalLight = new THREE.DirectionalLight( 0xffeedd );
			directionalLight.position.set( 0, 0.5, 0.5 );
			scene.add( directionalLight );

			var objLoader = new THREE.OBJLoader();

			objLoader.load( 'meshes/mesh/Mesh/ska6.obj', function( object ) {
			//	object.position.y = 1000;
			    object.traverse(function (node) {
					if (node.type === 'Mesh') level = node;
				});
			    scene.add(level);
			});

			objLoader.load( 'meshes/mesh/Mesh/mergeNav4.obj', function( object ) {
				var navmesh;
				object.traverse(function (node) {
					if (node.type === 'Mesh') navmesh = node;
				});

				var geometry = new THREE.Geometry();
				geometry.fromBufferGeometry(navmesh.geometry);
				var zoneNodes = patrol.buildNodes(geometry);

				patrol.setZoneData('level', zoneNodes);

				Object.assign(navmesh.material, {
					color: 0x009688,
					opacity: 0.5,
					transparent: true
				});

				scene.add(navmesh);

			// Set the player's navigation mesh group
				playerNavMeshGroup = patrol.getGroup('level', player.position);

			}); 
			
			var loader = new THREE.OBJLoader();

			// load a resource
			loader.load(
				// resource URL
				'meshes/mesh/Mesh/car/car.obj',
				// called when resource is loaded
				
				function ( object ) {
					object.scale.set(0.2,0.2,0.2);
					object.position.set(-4.5, 5.3, 5.6);
					scene.add( object );

				},
				
			);
			
	        // Add test sphere 
	        
			var geometry = new THREE.SphereGeometry( 0.5, 40, 40 );
			var material = new THREE.MeshBasicMaterial( {color: 0x00ff00} );
			player = new THREE.Mesh( geometry, material );
			scene.add( player );

			player.position.set(-3.5, 0.5, 5.5);
			
			// end point
			geometry = new THREE.BoxGeometry( 0.3, 0.3, 0.3 );
			var material = new THREE.MeshBasicMaterial( {color: 0xff0000} ); 
			target = new THREE.Mesh( geometry, material );
			scene.add( target );

			target.position.copy(player.position);

			// background
			renderer = new THREE.WebGLRenderer();
			renderer.setPixelRatio( window.devicePixelRatio );
			renderer.setSize( window.innerWidth, window.innerHeight );
			renderer.setClearColor(0xffffff);
			container.appendChild( renderer.domElement );

			raycaster = new THREE.Raycaster();

			document.addEventListener( 'click', onDocumentMouseClick, false );
			window.addEventListener( 'resize', onWindowResize, false );

			controls = new THREE.OrbitControls( camera );
			controls.damping = 0.2;

		}

		function onDocumentMouseClick (event) {

			// event.preventDefault();

			mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
			mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;

			camera.updateMatrixWorld();

			raycaster.setFromCamera( mouse, camera );

			var intersects = raycaster.intersectObject( level );

			if ( intersects.length > 0 ) {
				var vec = intersects[0].point;
				target.position.copy(vec);

				// Calculate a path to the target and store it
				calculatedPath = patrol.findPath(player.position, target.position, 'level', playerNavMeshGroup);

				if (calculatedPath && calculatedPath.length) {

					if (pathLines) {
						scene.remove(pathLines);
					}

					var material = new THREE.LineBasicMaterial({
						color: 0x0000ff,
						linewidth: 2
					});

					var geometry = new THREE.Geometry();
					geometry.vertices.push(player.position);

					// Draw debug lines
					for (var i = 0; i < calculatedPath.length; i++) {
						geometry.vertices.push(calculatedPath[i].clone().add(new THREE.Vector3(0, 0.2, 0)));
					}

					pathLines = new THREE.Line( geometry, material );
					scene.add( pathLines );

					// Draw debug cubes except the last one. Also, add the player position.
					var debugPath = [player.position].concat(calculatedPath);

					for (var i = 0; i < debugPath.length - 1; i++) {
						geometry = new THREE.BoxGeometry( 0.3, 0.3, 0.3 );
						var material = new THREE.MeshBasicMaterial( {color: 0x00ffff} );
						var node = new THREE.Mesh( geometry, material );
						node.position.copy(debugPath[i]);
						pathLines.add( node );
					}
				}
			}
		}

		function onWindowResize() {
			windowHalfX = window.innerWidth / 2;
			windowHalfY = window.innerHeight / 2;

			camera.aspect = window.innerWidth / window.innerHeight;
			camera.updateProjectionMatrix();

			renderer.setSize( window.innerWidth, window.innerHeight );
		}

		function animate() {
            var currTime = window.performance.now();
            var delta = (currTime - lastFrameTime) / 1000;
            var dTime = Math.min(delta, maxFrameTime);
            elapsedTime += delta;
            lastFrameTime = currTime;

            tick(dTime);

			requestAnimationFrame( animate );
			render();
		}

		function tick(dTime) {
			if (!level) {
				return;
			}

			var speed = 5;

			var targetPosition;

			if (calculatedPath && calculatedPath.length) {
				targetPosition = calculatedPath[0];

				var vel = targetPosition.clone().sub(player.position);

				if (vel.lengthSq() > 0.05 * 0.05) {
					vel.normalize();

					// Mve player to target
					player.position.add(vel.multiplyScalar(dTime * speed));
				}
				else {
					// Remove node from the path we calculated
					calculatedPath.shift();
				}
			}
		}

		function render() {
			camera.lookAt( scene.position );
			camera.updateMatrixWorld();

			renderer.render( scene, camera );

		}

	</script>



</body>

You really do need to make a live demo for this sort of question. It is extremely hard to debug hundreds of lines of code that we cannot run, because we don’t have the model, and each person who might potentially try to help you has to individually adapt your code and run it themselves.

If you do a little work to make it easier for others to help you, you’ll get help more quickly. Posting demos on sites like http://neocities.org/ is fairly easy to do, and free.

Also, it’s not clear what you are asking. The car variable that you load from the OBJ file is a mesh. Is something not working? Are there any errors in the console?