ShaneBrumback/threejs-examples-selecting-3d-minecraft-models-using-raycasters.html

## threejs-examples-selecting-3d-minecraft-models-using-raycasters.html
<!--////////////////////////////////////////////////////////////////////////////////////////
///                                                                                      ///
///  Example Using Three.js Library, HTML, CSS & JavaScript                              ///
//   3D Interactive Web Apps & Games 2021-2024                                           ///
///  Contact Shane Brumback https://www.shanebrumback.com                                ///
///  Send a message if you have questions about this code                                ///
///  I am a freelance developer. I develop any and all web.                              ///
///  Apps Websites 3D 2D CMS Systems etc. Contact me anytime :)                          ///
///                                                                                      ///
////////////////////////////////////////////////////////////////////////////////////////////-->


<!DOCTYPE html>
<html>
<head>
    <title>Three.js Examples - Selecting 3D Minecraft Models Using Raycasters</title>
    <meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">

</head>
<body>

    <script src="https://cdn.jsdelivr.net/npm/three@latest/build/three.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@latest/examples/js/controls/OrbitControls.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@latest/examples/js/loaders/GLTFLoader.js"></script>

    <script>

        // Set up the scene, camera, and renderer
        var scene = new THREE.Scene();
        var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);

        //Set up the renderer
        let renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true });
        renderer.setPixelRatio(window.devicePixelRatio);
        renderer.setSize(window.innerWidth, window.innerHeight);
        renderer.toneMapping = THREE.ReinhardToneMapping;
        renderer.shadowMap.enabled = true;
        renderer.shadowMap.type = THREE.PCFSoftShadowMap;
        renderer.domElement.id = 'renderer';
        renderer.setClearColor(0x000000, 1); // Set background color to black
        renderer.domElement.style.position = 'fixed';
        renderer.domElement.style.zIndex = '-1';
        renderer.domElement.style.left = '0';
        renderer.domElement.style.top = '0';
        document.body.appendChild(renderer.domElement);

        // Add ambient light
        var ambientLight = new THREE.AmbientLight(0xffffff, 0.5);
        scene.add(ambientLight);

        // Add directional light
        var directionalLight = new THREE.DirectionalLight(0xffffff, 0.5);
        directionalLight.position.set(1, 1, 1);
        scene.add(directionalLight);

        // Create a grid
        var gridHelper = new THREE.GridHelper(10, 10);
        scene.add(gridHelper);

        // Create a raycaster for interaction
        var raycaster = new THREE.Raycaster();
        var mouse = new THREE.Vector2();

        // Create a group for the model
        var modelGroup = new THREE.Group();
        scene.add(modelGroup);

        // Create a mixer for the animation
        var mixer;

        // Load GLTF model
        var loader = new THREE.GLTFLoader();
        loader.load('../models/gltf/minecraft-zombie/zombie-001.glb', function (gltf) {
          var model = gltf.scene;
            modelGroup.add(model);

            // Position and scale the model
            model.position.set(0, 0, 0);
            model.scale.set(1, 1, 1);

            // Calculate the bounding box of the model
            var boundingBox = new THREE.Box3().setFromObject(model);

            // Get the center of the bounding box
            var center = new THREE.Vector3();
            boundingBox.getCenter(center);

            // Get the size of the bounding box
            var size = new THREE.Vector3();
            boundingBox.getSize(size);

            // Calculate the distance to the model based on the bounding box size
            var maxDim = Math.max(size.x, size.y, size.z);
            var distance = maxDim / Math.tan(THREE.MathUtils.degToRad(camera.fov * 0.5));

            // Set the camera position and look at the center of the model
            camera.position.copy(center);
            camera.position.z += distance;
            camera.position.y += distance - 1.15;
            camera.lookAt(center);

            // Initialize OrbitControls
            var controls = new THREE.OrbitControls(camera, renderer.domElement);
            controls.autoRotate = true;
            controls.target.copy(center);

            // Get the animations from the GLTF model
            var animations = gltf.animations;

            // Create a mixer and assign it to the global mixer variable
            mixer = new THREE.AnimationMixer(model);

            // Play the first animation
            var action = mixer.clipAction(animations[1]);
            action.play();

            // Calculate the top position of the bounding box
            var topPosition = new THREE.Vector3();
            topPosition.addVectors(center, new THREE.Vector3(0, size.y / 2, 0));
        });

        // Handle mouse click
        function onMouseClick(event) {
            // Calculate mouse position in normalized device coordinates
            mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
            mouse.y = -(event.clientY / window.innerHeight) * 2 + 1;

            // Update the picking ray with the camera and mouse position
            raycaster.setFromCamera(mouse, camera);

            // Check for intersections only with the model group
            var intersects = raycaster.intersectObjects(modelGroup.children, true);

            if (intersects.length > 0) {
                alert('Clicked on the model!');
            }
        }

        // Add event listener for mouse click
        window.addEventListener('click', onMouseClick, false);

        // Render the scene
        function animate() {
            requestAnimationFrame(animate);

            // Update the mixer
            if (mixer) {
                mixer.update(0.02);
            }


            renderer.render(scene, camera);
        }
        animate();


        // Add window resize event listener
        window.addEventListener('resize', onWindowResize);

        // Function to handle window resize event
        function onWindowResize() {
            camera.aspect = window.innerWidth / window.innerHeight;
            camera.updateProjectionMatrix();
            renderer.setSize(window.innerWidth, window.innerHeight);
        }

    </script>
</body>
</html>
	<!--////////////////////////////////////////////////////////////////////////////////////////
	/// ///
	/// Example Using Three.js Library, HTML, CSS & JavaScript ///
	// 3D Interactive Web Apps & Games 2021-2024 ///
	/// Contact Shane Brumback https://www.shanebrumback.com ///
	/// Send a message if you have questions about this code ///
	/// I am a freelance developer. I develop any and all web. ///
	/// Apps Websites 3D 2D CMS Systems etc. Contact me anytime :) ///
	/// ///
	////////////////////////////////////////////////////////////////////////////////////////////-->



	<!DOCTYPE html>
	<html>
	<head>
	<title>Three.js Examples - Selecting 3D Minecraft Models Using Raycasters</title>
	<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">

	</head>
	<body>

	<script src="https://cdn.jsdelivr.net/npm/three@latest/build/three.min.js"></script>
	<script src="https://cdn.jsdelivr.net/npm/three@latest/examples/js/controls/OrbitControls.js"></script>
	<script src="https://cdn.jsdelivr.net/npm/three@latest/examples/js/loaders/GLTFLoader.js"></script>

	<script>

	// Set up the scene, camera, and renderer
	var scene = new THREE.Scene();
	var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);

	//Set up the renderer
	let renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true });
	renderer.setPixelRatio(window.devicePixelRatio);
	renderer.setSize(window.innerWidth, window.innerHeight);
	renderer.toneMapping = THREE.ReinhardToneMapping;
	renderer.shadowMap.enabled = true;
	renderer.shadowMap.type = THREE.PCFSoftShadowMap;
	renderer.domElement.id = 'renderer';
	renderer.setClearColor(0x000000, 1); // Set background color to black
	renderer.domElement.style.position = 'fixed';
	renderer.domElement.style.zIndex = '-1';
	renderer.domElement.style.left = '0';
	renderer.domElement.style.top = '0';
	document.body.appendChild(renderer.domElement);

	// Add ambient light
	var ambientLight = new THREE.AmbientLight(0xffffff, 0.5);
	scene.add(ambientLight);

	// Add directional light
	var directionalLight = new THREE.DirectionalLight(0xffffff, 0.5);
	directionalLight.position.set(1, 1, 1);
	scene.add(directionalLight);

	// Create a grid
	var gridHelper = new THREE.GridHelper(10, 10);
	scene.add(gridHelper);

	// Create a raycaster for interaction
	var raycaster = new THREE.Raycaster();
	var mouse = new THREE.Vector2();

	// Create a group for the model
	var modelGroup = new THREE.Group();
	scene.add(modelGroup);

	// Create a mixer for the animation
	var mixer;

	// Load GLTF model
	var loader = new THREE.GLTFLoader();
	loader.load('../models/gltf/minecraft-zombie/zombie-001.glb', function (gltf) {
	var model = gltf.scene;
	modelGroup.add(model);

	// Position and scale the model
	model.position.set(0, 0, 0);
	model.scale.set(1, 1, 1);

	// Calculate the bounding box of the model
	var boundingBox = new THREE.Box3().setFromObject(model);

	// Get the center of the bounding box
	var center = new THREE.Vector3();
	boundingBox.getCenter(center);

	// Get the size of the bounding box
	var size = new THREE.Vector3();
	boundingBox.getSize(size);

	// Calculate the distance to the model based on the bounding box size
	var maxDim = Math.max(size.x, size.y, size.z);
	var distance = maxDim / Math.tan(THREE.MathUtils.degToRad(camera.fov * 0.5));

	// Set the camera position and look at the center of the model
	camera.position.copy(center);
	camera.position.z += distance;
	camera.position.y += distance - 1.15;
	camera.lookAt(center);

	// Initialize OrbitControls
	var controls = new THREE.OrbitControls(camera, renderer.domElement);
	controls.autoRotate = true;
	controls.target.copy(center);

	// Get the animations from the GLTF model
	var animations = gltf.animations;

	// Create a mixer and assign it to the global mixer variable
	mixer = new THREE.AnimationMixer(model);

	// Play the first animation
	var action = mixer.clipAction(animations[1]);
	action.play();

	// Calculate the top position of the bounding box
	var topPosition = new THREE.Vector3();
	topPosition.addVectors(center, new THREE.Vector3(0, size.y / 2, 0));
	});

	// Handle mouse click
	function onMouseClick(event) {
	// Calculate mouse position in normalized device coordinates
	mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
	mouse.y = -(event.clientY / window.innerHeight) * 2 + 1;

	// Update the picking ray with the camera and mouse position
	raycaster.setFromCamera(mouse, camera);

	// Check for intersections only with the model group
	var intersects = raycaster.intersectObjects(modelGroup.children, true);

	if (intersects.length > 0) {
	alert('Clicked on the model!');
	}
	}

	// Add event listener for mouse click
	window.addEventListener('click', onMouseClick, false);

	// Render the scene
	function animate() {
	requestAnimationFrame(animate);

	// Update the mixer
	if (mixer) {
	mixer.update(0.02);
	}


	renderer.render(scene, camera);
	}
	animate();


	// Add window resize event listener
	window.addEventListener('resize', onWindowResize);

	// Function to handle window resize event
	function onWindowResize() {
	camera.aspect = window.innerWidth / window.innerHeight;
	camera.updateProjectionMatrix();
	renderer.setSize(window.innerWidth, window.innerHeight);
	}

	</script>
	</body>
	</html>