manual/examples/voxel-geometry-merged.html

<!-- 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 - Voxel Geometry - Merged</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
    }
    #c {
        width: 100%;
        height: 100%;
        display: block;
    }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
  </body>
<script type="importmap">
{
  "imports": {
    "three": "../../build/three.module.js",
    "three/addons/": "../../examples/jsm/"
  }
}
</script>

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

function main() {

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

	const cellSize = 256;

	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( cellSize / 2, 60, cellSize );

	const controls = new OrbitControls( camera, canvas );
	controls.target.set( cellSize / 2, 60, cellSize / 2 );
	controls.update();

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

	{

		const color = 0xFFFFFF;
		const intensity = 3;
		const light = new THREE.DirectionalLight( color, intensity );
		light.position.set( - 1, 2, 4 );
		scene.add( light );

	}

	const geometries = [];
	for ( let y = 0; y < cellSize; ++ y ) {

		for ( let z = 0; z < cellSize; ++ z ) {

			for ( let x = 0; x < cellSize; ++ x ) {

				const height = ( Math.sin( x / cellSize * Math.PI * 4 ) + Math.sin( z / cellSize * Math.PI * 6 ) ) * 20 + 60;
				//if (y < height) {
				if ( height > y && height < y + 1 ) {

					const geometry = new THREE.BoxGeometry( 1, 1, 1 );
					geometry.applyMatrix4( ( new THREE.Matrix4() ).makeTranslation( x, y, z ) );
					geometries.push( geometry );

				}

			}

		}

	}

	const mergedGeometry = BufferGeometryUtils.mergeGeometries(
		geometries, false );
	const material = new THREE.MeshPhongMaterial( { color: 'green' } );
	const mesh = new THREE.Mesh( mergedGeometry, material );
	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;

	}

	let renderRequested = false;

	function render() {

		renderRequested = undefined;

		if ( resizeRendererToDisplaySize( renderer ) ) {

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

		}

		controls.update();
		renderer.render( scene, camera );

	}

	render();

	function requestRenderIfNotRequested() {

		if ( ! renderRequested ) {

			renderRequested = true;
			requestAnimationFrame( render );

		}

	}

	controls.addEventListener( 'change', requestRenderIfNotRequested );
	window.addEventListener( 'resize', requestRenderIfNotRequested );

}

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