Three.js - CanvasRenderer not rendering Mesh with multiple materials

Question

I have a problem with CanvasRenderer rendering a Mesh that has multiple materials applied to a BoxBufferGeometry. It renders a Mesh with no materials applied. This is only problem with CanvasRenderer, when I use the same Mesh with WebGLRenderer all works as expected.

Here's an example code:

// three.js: multiple materials on a single mesh

var renderer, scene, camera, mesh;

init();
render();

function init() {

  // renderer
  renderer = new THREE.CanvasRenderer( { alpha: true } );
  renderer.setSize( window.innerWidth / 2, window.innerHeight );
  document.body.appendChild( renderer.domElement );

  // scene
  scene = new THREE.Scene();

  // camera
  camera = new THREE.PerspectiveCamera( 40, (window.innerWidth / 2) / window.innerHeight, 1, 1000 );
  camera.position.set( 15, 20, 30 );
  camera.lookAt(scene.position);
  scene.add( camera );


  // ambient
  scene.add( new THREE.AmbientLight( 0xffffff, 0.1 ) );

  // light
  camera.add( new THREE.PointLight( 0xffffff, 1 ) );

  // geometry
  var geometry = new THREE.BoxBufferGeometry( 10, 10, 10 );

  // materials
  var material0 = new THREE.MeshBasicMaterial({ color: 0xff0000 });
  var material1 = new THREE.MeshBasicMaterial({ color: 0x00ff00 });
  var material2 = new THREE.MeshBasicMaterial({ color: 0x0000ff });
  var material3 = new THREE.MeshBasicMaterial({ color: 0xffff00 });
  var material4 = new THREE.MeshBasicMaterial({ color: 0x00ffff });
  var material5 = new THREE.MeshBasicMaterial({ color: 0xff00ff });

  var materials = [ material0, material1, material2, material3, material4, material5 ];

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

}

function render() {
  requestAnimationFrame(render);
  mesh.rotation.x += 0.005;
  mesh.rotation.y += 0.01;
  renderer.render( scene, camera );
}

I've also made this fiddle

Where you can see exactly what I'm talking about. In the fiddle there's a Mesh(cube) that has all 6 groups(sides) in different material(color), and that same Mesh is rendered with WebGLRenderer(left) and CanvasRenderer(right).

Can someone with more experience help me understand this. Am I doing something wrong? Is there some limitation with CanvasRenderer that disables it to render such a Mesh, and if so, how would I achieve this effect in some other way? Is this a bug, and should I report it as an issue on three.js repository?

Thanks for your help!

Note: I'm new to Three.js, so I apologize if I made some obvious mistake. CanvasRenderer is crucial for me as I use phantom.js to capture some screenshots.

Three.js r93

WestLangley WestLangley · Accepted Answer · 2018-06-03T00:39:01

CanvasRenderer does not appear to support BufferGeometry and multi-materials.

A work-around is to use Geometry, instead.

var geometry = new THREE.BoxGeometry( 10, 10, 10 );

three.js r.93

Three.js - CanvasRenderer not rendering Mesh with multiple materials

1 Answers