JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://threejs.org/build/three.min.js"></script>

JavaScript

var canvas1 = document.createElement('canvas');
canvas1.setAttribute('id', 'one');
document.body.appendChild(canvas1);
var canvas2 = document.createElement('canvas');
document.body.appendChild(canvas2);
canvas2.setAttribute('id', 'two');
var renderer = new THREE.WebGLRenderer({
    canvas: canvas1
});
renderer.setSize(100,100);
var renderer2 = new THREE.WebGLRenderer({
    canvas: canvas2
});
renderer2.setSize(100,100);
var mesh = new THREE.Mesh(
    new THREE.BoxGeometry(100,100,100)
);
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera();
camera.position.z = 500;
scene.add(mesh);

function draw(){ 
    //try commenting the first render out
    //it will allow the other renderer to draw
    renderer.render(scene,camera); 
    renderer2.render(scene,camera);
    requestAnimationFrame(draw);
}
draw();