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Use threejs to create geometry, dynamically add geometry, delete geometry, and add coordinate axes

2022-07-05 04:00:00 【Zuo Ben】

 1, Introduce  

This example uses r95 edition Three.js library . You will create a scene and add geometry , Add geometry dynamically , Delete Geometry , Get all objects in the scene , Add axis . The renderings are as follows ： 

The introduction of the file ：

three.js  // threejs It's based on WebGL API Advanced based on API

dat.gui.js  // dat.GUI Provide operation interface , Easy to debug

OrbitControls.js  // Track controller , Used to control the rotation and translation of objects in the scene

Description of main components ：

The camera ： Decide what needs to be rendered on the screen

Renderers ： Based on camera and scene , Call the underlying layer api Perform drawing work

object ： They are the main rendered objects , Like a square 、 sphere , Axis

2, Sample source code ：

<!DOCTYPE html>
<html>
	<head>
		<title> Use threejs Create geometry and add axes </title>
		<script type="text/javascript" src="../libs/three.js"></script>
		<script type="text/javascript" src="../libs/dat.gui.js"></script>
		<script type="text/javascript" src="../libs/OrbitControls.js"></script>
		<style>
			body {
				margin: 0;
				overflow: hidden;
			}
		</style>
	</head>
	<body>
		<div id="dom"></div>
		<script type="text/javascript">
			var camera;
			var renderer;
			function init() {
				//  Create a scene , It will contain all our elements , Like an object , Cameras and lights .
				var scene = new THREE.Scene();

				//  Create a camera , It defines where we are looking 
				camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
				//  Aim the camera at the center of the scene 
				camera.position.x = 10;
				camera.position.y = 50;
				camera.position.z = 90;
				camera.lookAt(scene.position);
				var orbit = new THREE.OrbitControls(camera);

				//  Create a renderer and set the size ,WebGLRenderer The computer graphics card will be used to render the scene 
				renderer = new THREE.WebGLRenderer();
				renderer.setClearColor(new THREE.Color(0xEEEEEE));
				renderer.setSize(window.innerWidth, window.innerHeight);
				//  Setting up the renderer requires shadow effects 
				renderer.shadowMapEnabled = true;

				//  Display the coordinate axis on the screen 
				var axes = new THREE.AxisHelper(100);
				scene.add(axes);

				//  Add planes to the scene 
				var plane = createPlaneGeometryBasicMaterial();
				scene.add(plane);

				//  Add the cube to the scene 
				var cube = createBoxGeometryBasicMaterial();
				scene.add(cube);

				//  Add a sphere to the scene 
				var sphere = createSphereGeometryLambertMaterial();
				scene.add(sphere);

				//  Add the output of the renderer to HTML Elements 
				document.getElementById("dom").appendChild(renderer.domElement);
				
				//  Use GUI Debug library 
				var controls = new function () {
					this.numberOfObjects = scene.children.length;
					//  Randomly generate a cube 
					this.addCube = function () {
					    //  Add the cube to the scene 
					    scene.add(createBoxGeometryLambertMaterial());
						//  Update the number of objects in the interface 
					    this.numberOfObjects = scene.children.length;
					};
					
					//  Remove objects from the scene , Remove the last object added to the scene 
					this.removeCube = function () {
						//  Get all objects in the scene 
						var allChildren = scene.children;
						var lastObject = allChildren[allChildren.length - 1];
						//  Remove only THREE.Mesh object 
						if (lastObject instanceof THREE.Mesh && lastObject != plane && lastObject != cube && lastObject != sphere) {
							scene.remove(lastObject);
							//  Update the number of objects in the interface 
							this.numberOfObjects = scene.children.length;
						}
					};
					
					//  Print all objects in the scene 
					this.outputObjects = function () {
						console.log(scene.children);
					}
				};
				var gui = new dat.GUI();
				//  Add event 
				gui.add(controls, 'addCube');
				gui.add(controls, 'removeCube');
				gui.add(controls, 'outputObjects');
				//  Listening variables 
				gui.add(controls, 'numberOfObjects').listen();
				
				//  Start animation 
				renderScene();
				
				//  Create a cube of random size and color 
				function createBoxGeometryLambertMaterial() {
					var cubeSize = Math.ceil((Math.random() * 3));
					//  Create a cube and set the size 
					var cubeGeometry = new THREE.BoxGeometry(cubeSize, cubeSize, cubeSize);
					// MeshBasicMaterial Set the material 
					var cubeMaterial = new THREE.MeshBasicMaterial({
						color: Math.random() * 0xffffff,
						wireframe: true //  linear 
					});
					var cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
					//  Set the object to cast shadows 
					cube.castShadow = true;
					//  Set the name of the cube 
					cube.name = "cube-" + scene.children.length;
					//  Set cube position 
					cube.position.x = -30 + Math.round((Math.random() * 60));
					cube.position.y = Math.round((Math.random() * 5));
					cube.position.z = -20 + Math.round((Math.random() * 20));
					return cube;
				}
				//  Create a cube of base material 
				function createBoxGeometryBasicMaterial() {
					//  Create a cube and set the size 
					var cubeGeometry = new THREE.BoxGeometry(4, 4, 4);
					var cubeMaterial = new THREE.MeshBasicMaterial({
						color: 0xff0000,
						wireframe: true //  linear 
					});
					var cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
					//  Set cube position 
					cube.position.x = -10;
					cube.position.y = 3;
					cube.position.z = 0;
					return cube;
				}
				//  Create a plane 
				function createPlaneGeometryBasicMaterial() {
					//  Create the ground plane and set the size 
					var planeGeometry = new THREE.PlaneGeometry(100, 70);
					var planeMaterial = new THREE.MeshBasicMaterial({
						color: 0xcccccc
					});
					var plane = new THREE.Mesh(planeGeometry, planeMaterial);
			
					//  Set the plane position and rotate 
					plane.rotation.x = -0.5 * Math.PI;
					plane.position.x = 0;
					plane.position.y = 0;
					plane.position.z = 0;
					return plane;
				}
				//  Create a spherical geometry 
				function createSphereGeometryLambertMaterial() {
					//  Create a sphere 
					var sphereGeometry = new THREE.SphereGeometry(4, 20, 20);
					var sphereMaterial = new THREE.MeshBasicMaterial({
						color: 0x7777ff,
						wireframe: true //  linear 
					});
					var sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);
					//  Location range 
					sphere.position.x = 20;
					sphere.position.y = 4;
					sphere.position.z = 2;
					return sphere;
				}
				
				function renderScene() {
					orbit.update();
				    //  Use requestAnimationFrame Function to render 
				    requestAnimationFrame(renderScene);
				    renderer.render(scene, camera);
				}

				//  Rendered scenes 
				renderer.render(scene, camera);
			}
			window.onload = init;
			
			//  Modify the scene as the form changes 
			function onResize() {
			    camera.aspect = window.innerWidth / window.innerHeight;
			    camera.updateProjectionMatrix();
			    renderer.setSize(window.innerWidth, window.innerHeight);
			}
			//  Listen for form resizing events 
			window.addEventListener('resize', onResize, false);
		</script>
	</body>
</html>

If you need a complete code, please leave a message or contact me on wechat ：1171053128

原网站

版权声明
本文为[Zuo Ben]所创，转载请带上原文链接，感谢
https://yzsam.com/2022/02/202202140717141316.html

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