javascript
/
three.js
mirror of https://github.com/tazdij/three.js.git


			
				
					
						
						
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							<!-- Licensed under a BSD license. See license.html for license -->
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
    <title>Three.js - Billboard Trees Static Billboards</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
    }
    #c {
        width: 100%;
        height: 100%;
        display: block;
    }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
  </body>
<!-- Import maps polyfill -->
<!-- Remove this when import maps will be widely supported -->
<script async src="https://unpkg.com/[email protected]/dist/es-module-shims.js"></script>

<script type="importmap">
{
  "imports": {
    "three": "../../build/three.module.js",
    "three/addons/": "../../examples/jsm/"
  }
}
</script>

<script type="module">
import * as THREE from 'three';
import { OrbitControls } from 'three/addons/controls/OrbitControls.js';

function main() {

	const canvas = document.querySelector( '#c' );
	const renderer = new THREE.WebGLRenderer( { antialias: true, canvas } );
	renderer.useLegacyLights = false;

	const fov = 75;
	const aspect = 2; // the canvas default
	const near = 0.1;
	const far = 1000;
	const camera = new THREE.PerspectiveCamera( fov, aspect, near, far );
	camera.position.set( 0, 2, 5 );

	const controls = new OrbitControls( camera, canvas );
	controls.target.set( 0, 2, 0 );
	controls.minPolarAngle = 0;
	controls.maxPolarAngle = Math.PI / 2;
	controls.update();

	const scene = new THREE.Scene();

	function addLight( position ) {

		const color = 0xFFFFFF;
		const intensity = 3;
		const light = new THREE.DirectionalLight( color, intensity );
		light.position.set( ...position );
		scene.add( light );
		scene.add( light.target );

	}

	addLight( [ - 3, 1, 1 ] );
	addLight( [ 2, 1, .5 ] );

	const trunkRadius = .2;
	const trunkHeight = 1;
	const trunkRadialSegments = 12;
	const trunkGeometry = new THREE.CylinderGeometry(
		trunkRadius, trunkRadius, trunkHeight, trunkRadialSegments );

	const topRadius = trunkRadius * 4;
	const topHeight = trunkHeight * 2;
	const topSegments = 12;
	const topGeometry = new THREE.ConeGeometry(
		topRadius, topHeight, topSegments );

	const trunkMaterial = new THREE.MeshPhongMaterial( { color: 'brown' } );
	const topMaterial = new THREE.MeshPhongMaterial( { color: 'green' } );

	function makeTree( x, z ) {

		const root = new THREE.Object3D();
		const trunk = new THREE.Mesh( trunkGeometry, trunkMaterial );
		trunk.position.y = trunkHeight / 2;
		root.add( trunk );

		const top = new THREE.Mesh( topGeometry, topMaterial );
		top.position.y = trunkHeight + topHeight / 2;
		root.add( top );

		root.position.set( x, 0, z );
		scene.add( root );

		return root;

	}

	function frameArea( sizeToFitOnScreen, boxSize, boxCenter, camera ) {

		const halfSizeToFitOnScreen = sizeToFitOnScreen * 0.5;
		const halfFovY = THREE.MathUtils.degToRad( camera.fov * .5 );
		const distance = halfSizeToFitOnScreen / Math.tan( halfFovY );

		camera.position.copy( boxCenter );
		camera.position.z += distance;

		// pick some near and far values for the frustum that
		// will contain the box.
		camera.near = boxSize / 100;
		camera.far = boxSize * 100;

		camera.updateProjectionMatrix();

	}

	function makeSpriteTexture( textureSize, obj ) {

		const rt = new THREE.WebGLRenderTarget( textureSize, textureSize );

		const aspect = 1; // because the render target is square
		const camera = new THREE.PerspectiveCamera( fov, aspect, near, far );

		scene.add( obj );

		// compute the box that contains obj
		const box = new THREE.Box3().setFromObject( obj );

		const boxSize = box.getSize( new THREE.Vector3() );
		const boxCenter = box.getCenter( new THREE.Vector3() );

		// set the camera to frame the box
		const fudge = 1.1;
		const size = Math.max( ...boxSize.toArray() ) * fudge;
		frameArea( size, size, boxCenter, camera );

		renderer.autoClear = false;
		renderer.setRenderTarget( rt );
		renderer.render( scene, camera );
		renderer.setRenderTarget( null );
		renderer.autoClear = true;

		scene.remove( obj );

		return {
			offset: boxCenter.multiplyScalar( fudge ),
			scale: size,
			texture: rt.texture,
		};

	}

	// make billboard texture
	const tree = makeTree( 0, 0 );
	const facadeSize = 64;
	const treeSpriteInfo = makeSpriteTexture( facadeSize, tree );

	function makeSprite( spriteInfo, x, z ) {

		const { texture, offset, scale } = spriteInfo;
		const mat = new THREE.SpriteMaterial( {
			map: texture,
			transparent: true,
		} );
		const sprite = new THREE.Sprite( mat );
		scene.add( sprite );
		sprite.position.set(
			offset.x + x,
			offset.y,
			offset.z + z );
		sprite.scale.set( scale, scale, scale );

	}

	for ( let z = - 50; z <= 50; z += 10 ) {

		for ( let x = - 50; x <= 50; x += 10 ) {

			makeSprite( treeSpriteInfo, x, z );

		}

	}

	scene.background = new THREE.Color( 'lightblue' );

	{

		const size = 400;
		const geometry = new THREE.PlaneGeometry( size, size );
		const material = new THREE.MeshPhongMaterial( { color: 'gray' } );
		const mesh = new THREE.Mesh( geometry, material );
		mesh.rotation.x = Math.PI * - 0.5;
		scene.add( mesh );

	}

	function resizeRendererToDisplaySize( renderer ) {

		const canvas = renderer.domElement;
		const width = canvas.clientWidth;
		const height = canvas.clientHeight;
		const needResize = canvas.width !== width || canvas.height !== height;
		if ( needResize ) {

			renderer.setSize( width, height, false );

		}

		return needResize;

	}

	function render() {

		if ( resizeRendererToDisplaySize( renderer ) ) {

			const canvas = renderer.domElement;
			camera.aspect = canvas.clientWidth / canvas.clientHeight;
			camera.updateProjectionMatrix();

		}

		renderer.render( scene, camera );

		requestAnimationFrame( render );

	}

	requestAnimationFrame( render );

}

main();
</script>
</html>