JSFiddle - React, Tailwind, and code Playground

by navinleon

HTML

<script src="//cdn.rawgit.com/mrdoob/three.js/master/build/three.js"></script>
<script src="//threejsfundamentals.org/threejs/resources/threejs/r119/examples/jsm/utils/BufferGeometryUtils.js"></script>

CSS

body {
	  margin: 0;
}

JavaScript

var camera, scene, renderer;

init();
animate();

function init() {

    camera = new THREE.PerspectiveCamera( 70, window.innerWidth / window.innerHeight, 0.01, 10 );
    camera.position.z = 4;

    scene = new THREE.Scene();

    var boxGeometry = new THREE.BoxBufferGeometry();
		boxGeometry = boxGeometry.toNonIndexed(); // ensure non-indexed geometry for merging
		boxGeometry.translate( - 2, 0, 0 );
		
		var triangleGeometry = generateTriangleGeometry();
		triangleGeometry.translate( 2, 0, 0 );
		
		var geometry = THREE.BufferGeometryUtils.mergeBufferGeometries( [ boxGeometry, triangleGeometry ] );
		
    material = new THREE.MeshNormalMaterial();

    mesh = new THREE.Mesh( geometry, material );
    scene.add( mesh );

    renderer = new THREE.WebGLRenderer( { antialias: true } );
    renderer.setSize( window.innerWidth, window.innerHeight );
    document.body.appendChild( renderer.domElement );

}

function animate() {

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

}

function generateTriangleGeometry() {

	var geometry = new THREE.BufferGeometry();
	var vertices = [];

	vertices.push( - 1, - 1, 0 );
	vertices.push( 1, - 1, 0 );
	vertices.push( 1, 1, 0 );

	geometry.addAttribute( 'position', new THREE.Float32BufferAttribute( vertices, 3 ) );
	geometry.computeVertexNormals();

	return geometry;

}