pages/tenMinutePhysics/02-cannonball3d.html at master · matthias-research/pages · GitHub

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<!--
Copyright 2021 Matthias Müller - Ten Minute Physics

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-->

<!DOCTYPE html>
<html lang="en">
	<head>
		<title>Cannonball 3d</title>
		<style>
		body {
			font-family: verdana;
			font-size: 15px;
		}
		</style>
	</head>

	<body>

        <h1>Cannonball 3d</h1>
		<button id = "buttonRun" onclick="run()" class="button">Run</button>
		<button onclick="restart()" class="button">Restart</button>

		<br><br>
        <div id="container"></div>

        <script src="https://unpkg.com/three@0.139.2/build/three.min.js"></script>
        <script src="https://unpkg.com/three@0.139.2/examples/js/controls/OrbitControls.js"></script>
		<script>

			var threeScene;
			var renderer;
			var camera;
			var cameraControl;

            // ------------------------------------------------------------------

			// physics scene

			var physicsScene =
			{
				gravity : new THREE.Vector3(0.0, -10.0, 0.0),
				dt : 1.0 / 60.0,
				worldSize : { x: 1.5, z : 2.5 },
				paused: true,
				objects: [],
			};

			// ------------------------------------------------------------------
			class Ball {
				constructor(pos, radius, vel, scene)
				{
					// physics data

                    this.pos = pos;
                    this.radius = radius;
                    this.vel = vel;

					// visual mesh

                    var geometry = new THREE.SphereGeometry( radius, 32, 32 );
                    var material = new THREE.MeshPhongMaterial({color: 0xff0000});
                    this.visMesh = new THREE.Mesh( geometry, material );
					this.visMesh.position.copy(pos);
                    threeScene.add(this.visMesh);
				}

				simulate()
				{
					this.vel.addScaledVector(physicsScene.gravity, physicsScene.dt);
					this.pos.addScaledVector(this.vel, physicsScene.dt);

					if (this.pos.x < -physicsScene.worldSize.x) {
						this.pos.x = -physicsScene.worldSize.x; this.vel.x = -this.vel.x;
					}
					if (this.pos.x >  physicsScene.worldSize.x) {
						this.pos.x =  physicsScene.worldSize.x; this.vel.x = -this.vel.x;
					}
					if (this.pos.z < -physicsScene.worldSize.z) {
						this.pos.z = -physicsScene.worldSize.z; this.vel.z = -this.vel.z;
					}
					if (this.pos.z >  physicsScene.worldSize.z) {
						this.pos.z =  physicsScene.worldSize.z; this.vel.z = -this.vel.z;
					}
					if (this.pos.y < this.radius) {
						this.pos.y = this.radius; this.vel.y = -this.vel.y;
					}

					this.visMesh.position.copy(this.pos);
				}
			}

			// ------------------------------------------------------------------
			function initPhysics(scene)
			{
				var radius = 0.2;
				var pos = new THREE.Vector3(radius, radius, radius);
				var vel = new THREE.Vector3(2.0, 5.0, 3.0);

				physicsScene.objects.push(new Ball(pos, radius, vel, scene));
			}

			// ------------------------------------------------------------------
			function simulate()
			{
				if (physicsScene.paused)
					return;
				for (var i = 0; i < physicsScene.objects.length; i++)
					physicsScene.objects[i].simulate();
			}

			// ------------------------------------------

			function initThreeScene()
			{
				threeScene = new THREE.Scene();

				// Lights

				threeScene.add( new THREE.AmbientLight( 0x505050 ) );
				threeScene.fog = new THREE.Fog( 0x000000, 0, 15 );

				var spotLight = new THREE.SpotLight( 0xffffff );
				spotLight.angle = Math.PI / 5;
				spotLight.penumbra = 0.2;
				spotLight.position.set( 2, 3, 3 );
				spotLight.castShadow = true;
				spotLight.shadow.camera.near = 3;
				spotLight.shadow.camera.far = 10;
				spotLight.shadow.mapSize.width = 1024;
				spotLight.shadow.mapSize.height = 1024;
				threeScene.add( spotLight );

				var dirLight = new THREE.DirectionalLight( 0x55505a, 1 );
				dirLight.position.set( 0, 3, 0 );
				dirLight.castShadow = true;
				dirLight.shadow.camera.near = 1;
				dirLight.shadow.camera.far = 10;

				dirLight.shadow.camera.right = 1;
				dirLight.shadow.camera.left = - 1;
				dirLight.shadow.camera.top	= 1;
				dirLight.shadow.camera.bottom = - 1;

				dirLight.shadow.mapSize.width = 1024;
				dirLight.shadow.mapSize.height = 1024;
				threeScene.add( dirLight );

				// Geometry

				var ground = new THREE.Mesh(
					new THREE.PlaneBufferGeometry( 20, 20, 1, 1 ),
					new THREE.MeshPhongMaterial( { color: 0xa0adaf, shininess: 150 } )
				);

				ground.rotation.x = - Math.PI / 2; // rotates X/Y to X/Z
				ground.receiveShadow = true;
				threeScene.add( ground );

				var helper = new THREE.GridHelper( 20, 20 );
				helper.material.opacity = 1.0;
				helper.material.transparent = true;
				helper.position.set(0, 0.002, 0);
				threeScene.add( helper );

				// Renderer

				renderer = new THREE.WebGLRenderer();
				renderer.shadowMap.enabled = true;
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( 0.8 * window.innerWidth, 0.8 * window.innerHeight );
				window.addEventListener( 'resize', onWindowResize, false );
				container.appendChild( renderer.domElement );

				// Camera

				camera = new THREE.PerspectiveCamera( 70, window.innerWidth / window.innerHeight, 0.01, 100);
			    camera.position.set(0, 1, 4);
				camera.updateMatrixWorld();

				threeScene.add( camera );

				cameraControl = new THREE.OrbitControls(camera, renderer.domElement);
    			cameraControl.zoomSpeed = 2.0;
    			cameraControl.panSpeed = 0.4;
			}

			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();
				renderer.setSize( window.innerWidth, window.innerHeight );
			}

			function run() {
				var button = document.getElementById('buttonRun');
				if (physicsScene.paused)
					button.innerHTML = "Stop";
				else
					button.innerHTML = "Run";
				physicsScene.paused = !physicsScene.paused;
			}

			function restart() {
				location.reload();
			}

			// make browser to call us repeatedly -----------------------------------

			function update() {
				simulate();
				renderer.render(threeScene, camera);
				cameraControl.update();

				requestAnimationFrame(update);
			}

			initThreeScene();
			initPhysics();
			update();

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